Everyone is hating on Coteaz and using henchmen as Troops right? Well suck it up. Time to look at what we can do with cheapy HQs or the Inquisitors! Stelek has done a very good list in this regard at 1500 points (though I'd take Chimeras on the Henchmen so they can drive onto the board during DoW, silly TDA Inquisitor!) revolving completely around the MSU concept. I'd like to move away from MSU somewhat and see what we can't do at 1750/2000 points. I'm not going to the full extreme Mike has with only full-sized squads as some flexibility is obviously gained by having more units but the durability full squads can offer is also enticing. Let's see if we can't combine the two then whilst maximising our potential points we can shove into midfield.
I'm going to start with a very basic core of Grey Knight Strike squads. These guys are quite expensive (their general setup being 90 points more than a Tactical squad) but have a bunch more firepower at range than Tacticals and much more fearsome in combat with the added utility of Warp Quake and the general all-round awesome of psycannons. However, like all Grey Knights, whilst they are more expensive they still die just like other Marines. We pay a premium for more offensive output but don't have huge gains in survivability (oh hi Dark Eldar!). Luckily we are at least MEQ and removing lots of these guys at once isn't always a walk in the park.
So there are two schools of thought on how to run GKSS.
MSU where only five Grey Knights are taken along with a psycannon and PsyBack. This is pretty cheap (160 points) and provides good firepower (2-4 S7 rending shots and 3 S6 twin-linked shots + 8 S4 shots) which can fire at two separate targets and when taken en masse, allows for a lot of flexibility in the army. When one unit dies, there are others waiting to take its place.
On the other hand we have larger squads. This is much more expensive and more of a 'swiss army knife' with better firepower (two psycannons and S5 stormbolters), survivability and capability in combat due to numbers and potential combat upgrades (i.e. Daemonhammer). However, firepower is lost as a Razorback upgrade becomes inefficient in some cases (you don't want to be forced to disembark). You can obviously still fire from the top-hatch of the Rhino but you're not maximising your damage potential with your free FoC slot granted by a dedicated transport. However, the larger squad also benefits much more greatly from abilities like Quicksilver, Hammerhand and Might as there are more bodies to use it.
And here's something to remember for all Grey Knights. They work very well outside of their transports. Of course they aren't required to get out and top hatches on Rhinos don't mean they always will at times but unlike MSU style Blood Angel and Space Wolf armies, Grey Knights are very capable of fighting outside their transports and are in fact comfortable doing it. Remember, we are paying extra points for our Marines so we need to get the most out of them and if they have storm bolters why not use them? Power weapons are there if the enemy gets close enough for combat as well.
Edit: SneakyDan just said this very well. I'll quote some of what he said.
"The thing a lot of people arent getting with psyback (or plasback, which i prefer) + purifier or GK combo, is that you arent driving up, and only deploying if something gets close enough to melta. Its not BA and Wolves people. You drive up 6, or 12 possibly, deploy your dudes, and open fire. Your opponent then has to deal with the tank, and the well equipped infantry next to said tank, and they are
BOTH pouring out quality fire power."
With this in mind can we make an effective list with both MSU and larger squads working together? I think so. So let's start with a core of two large squads and two smaller squads. We'll use the basic framework of 10x GKSS w/2x psycannons, psybolt ammunition, MC hammer, Rhino for our large squad and 5x GKSS w/psycannon, Razorback w/psybolt ammunition for the MSU squad. Psybolt ammo ends up costing 2 points per model on the larger squad which isn't cheap but a squad shooting nothing but S5/S7 shots is pretty good. The Hammer is in there because unlike Tacticals, large squads of GKSS aren't completely useless in combat. Taking two of each will set us back 910 points and we've got our Troops set and ready.
Now we have to decide where we go from here. Adding more midfield power is obviously what Grey Knights are very good at and we can do this in a lot of ways using just Grey Knight models without even broaching the Henchmen side of things. For the moment though let's see if we can't support our midfield elements with some ranged support and this of course means Psyflemen! We have two options as usual with Psyflemen, Venerable Dreads and normal Dreads and which one we use depends upon what other slot we want to utilise. In this list I think I'm going to want some Purifiers so we'll use normal Dreads who are significantly cheaper but more vulnerable to melta fire. Three of these sets us back 405 points for a total of 1315 used.
I said I wanted to use Purifiers so let's take a look at these. Unlike in my normal lists where I use these guys as an all-rounder unit, Purifiers here are acting as GKSS with access to more firepower, i.e. two psycannons per five guys. We can make these guys a bit scarier in combat with some cheap halberds but really they are more of a horde deterrent and accessing more psycannons so we'll take three squads with two psycannons and a Psyback for 190 each taking us to 1885.
This doesn't leave us much room to play with for our HQ. There are some very cheap choices in our Inquisitors and we could simply take one of these boys bare bones and go from there. This would give us a lot of ability to play around with our mech so we might leave this option for full MSU to ensure we have as many points as possible to stick into our infantry + tanks. For now let's drop a Purifier squad which takes us to 1695 points and see what we can do from there. Let's remind ourselves where our list stands currently.
2x5x Purifiers w/2x psycannons, Psyback
2x10x GKSS w/2x psycannons, psybolt, MC hammer, Rhino
2x5x GKSS w/psycannon, Psyback
3x Psyflemen
Pretty decent number of infantry, tanks and psycannons there with Dreads for ranged support and we've got 305 points to play around with for our HQs. This gives us enough points to access at least one of the GK based HQs in the Librarian or Grandmaster. The GM with scout and scoring options would be great to have as we can move to midfield and pop smoke before the game or generate backfield scoring units in the Dreadnoughts. The Librarian adds a ton of utility though and importantly can make any single large squad of GKSS very potent in combat whilst increasing midfield survivability. Both have access to servo skulls which are great utility but the GM has grenade options, though since we aren't really building an assault force they have less use here. The problem with both of these choices is they start with Terminator armor. This means they need a unit to hang out with on foot to begin the game or a transport which can carry them.
We don't have the points for a decent sized Paladin or GKT squad nor multiple Land Raiders or Storm Ravens but we probably have the points to fit in an Inquisitor + Henchmen squad with a Chimera. Only one is an issue but much less so with a Chimera compared to a Land Raider or Storm Raven and once the Henchmen unit disembarks in midfield, the Chimera is less of a target to your opponents. The important thing about the Chimera if you take a Librarian is that 6" bubble is that much bigger.
Let's see then if we can't take a Librarian and an Inquisitor unit with Chimera then. We've gone with the Librarian here over the Grandmaster due to the increased offensive and defensive ability the Librarian provides the midfield units. We'll take the Librarian with four powers, Shrouding, Sanctuary, Might and Quicksilver. Might + Quicksilver + Hammerhand on a large GKSS squad make them very potent in combat whilst Shrouding and Sanctuary improve the defenses of the units in midfield. This costs 170 points and we won't take skulls for the moment as we can get cheaper ones on the Inquisitor. This leaves 135 points for the Henchmen/Inquisitor combo which is down to 80 after we buy the Chimera.
This isn't a lot of points so we might have to shave things elsewhere but let's see what it can get us for the moment. We are looking at having a shooty henchmen unit which brings as much melta to the table as possible really but we don't want to overload on melta as the unit can only target one squad. We'll start then with just the basic Inquisitor cost and three Multi-melta servitors for a paltry 55 points. This gives us 3 BS3 MM which is pretty good if not perfectly reliable. We also wanted servo-skulls so we'll grab three of them from the Inquisitor which leaves us with 16 points to play with for the rest of the unit. That's jack diddly really and we'll just grab four Acolytes to fill out the squad.
The end result -
Librarian w/Shrouding, Sanctuary, Quicksilver, Might of Titan
Inquisitor w/3x servo-skulls
Henchmen 3x Servitors w/MM, 4x Warrior Acolytes, Chimera
5x Purifiers w/2x psycannons, Razorback w/psybolt ammunition
5x Purifiers w/2x psycannons, Razorback w/psybolt ammunition
10x Grey Knight Strike Squad w/2x psycannons, psybolt ammunition, MC hammer, Rhino
10x Grey Knight Strike Squad w/2x psycannons, psybolt ammunition, MC hammer, Rhino
5x Grey Knight Strike Squad w/psycannon, Razorback w/psybolt ammunition
5x Grey Knight Strike Squad w/psycannon, Razorback w/psybolt ammunition
Dreadnought w/2x twin-linked autocannons, psybolt ammunition
Dreadnought w/2x twin-linked autocannons, psybolt ammunition
Dreadnought w/2x twin-linked autocannons, psybolt ammunition
Totals: 2000 points
49 infantry
10 tanks
Now there are obviously lots of options to fiddle with this list as you see fit. Most of these fiddles aim at expanding the henchmen unit. These include dropping psybolts from the GKSS, dropping to two psyfledreads, replacing the Inquisitor with Coteaz to try and get two scoring henchmen units (neh at this option to be honest), replacing the Librarian with a 2nd inquisitor and henchmen unit (and obviously expanding both henchmen units with the extra points), etc. You could also just get rid of the Inquisitor + Henchmen option and look at creating a foot unit in which to place the Librarian but I think the Chimera hull radius really helps him out.
So the list itself... like most Grey Knight lists it is midfield based and the Librarian really adds to this. Having both MSU and larger Grey Knight squads with the option to combat squad really gives you flexibility in scoring and how you approach the game. Combine this with the Librarian's buffing powers in combat and you've got a lot of options. This is all backed up by the ever useful Psyflemen to provide ranged suppression and extra psychic defense against offensive powers.