The Review -
Now here's a tank which breaks the mould for Eldar. It's still a fast skimmer (tank) with AV12/12/10 and BS3 but (!) comes with multiple heavy weapon systems + the chin shuriken cannon option and has a transport capacity. Best of both worlds thank you very much! That being said, the options for the heavy weapons are more limited compared to say the War Walkers or Hornets - the Falcon automatically comes with one pulse laser and the upgrade point for the chin cannon - this leaves the player with only one heavy weapon option and you get the usual array of choices here as well.
There are two main schools of thought for what to take here - the ususal S6 spam which means a cheap as chips Shuriken Cannon or the improved range/rate of fire of the Scatter Laser or a heavy gun platform with a Missile Launcher to provide three S8 shots at once (or two S8 + a defensive S4 blast). The latter is more expensive but gives you more impressive anti-tank options whilst retaining some anti-infantry whilst the former is cheaper, gets more shots, etc. The other options available to the Falcon (Bright Lance or Starcannon) are just too expensive for what they provide as per usual and thus should be skipped.
The Falcon also comes with the usual assortment of potential Eldar upgrades and for once, some of them are quite viable. The chin cannon is always a good buy at 10 points and gives the Falcon an effective three heavy weapons - thank you very much. Vectored Engines aren't really worth it - entanglement is gone and skimmers are only destroyed on immobilised results when going flat out. Star Engines are like-wise lack lusture, you lose your shooting on a gun boat which wants to be shooting. Holo-fields however, well they increase the durability of the tank quite a bit and since the Falcon has multiple heavy weapon systems AND a transport capacity, keeping it alive at the cost of weapons is a much better proposition than for the Fire Prism. This also makes Spirit Stones a very effective upgrade as the Falcon becomes most likely to be shaken or lose a weapon from non-AP1 damage sources.
This makes the Falcon a very expensive but very durable gunboat with transport capacity. The holo-fields aren't required but this is basically the best use of the Falcon - fire support with the ability to carry around a smaller squad.
Potential Uses -
That transport capacity is misleading though, as is the silly fluff. Don't put crack squads of Aspect Warriors in here such as Fire Dragons or the 'combat' Aspects because the Falcon is at its best when flying circles around your opponent. Serpents are cheaper and more durable against the most common anti-tank gun in the game (the meltagun) thanks to their Energy Fields and therefore make much better short-ranged delivery systems (i.e. Fire Dragons). Due to the Falcon's survivability at range thanks to Holo-fields, it becomes a much better platform to screen the Eldar army early (more durable than Serpents at range expect against a few weapons such as Exorcist Missile Launchers) and a very durable gunboat throughout the game. This makes it an excellent choice for a small Troops squad to essentially make the Falcon a scoring unit - five Dire Avengers please!
Now, this is not to say NEVER send the Falcon into your opponent. Sometimes there are great benefits from doing so but you as the controlling player need to identify and capitalise on them. Rather, as a general rule of thumb, Serpents are for close in work and Falcons for hanging back. This gets a lot muddier of course if you don't bring Holo-fields on the Falcons but they are still bringing more firepower per point compared to the Wave Serpents who also have melt-protection. Take that as you will.
Falcons, as does most of the Eldar army, benefit greatly from Farseer support. Their paltry BS3 can be overcome and they have enough weapon systems to make this actually beneficial. In a full Mechdar list, they are often going to be the best targets for such unless one is running around with Vyper squadrons (or Hornets). And thanks to the transport capacity, the Farseer can sit inside and cast away quite happily as well (though this is now in excess of 350 points in one spot, be careful).
Potential Changes -
The Falcon as it is pretty solid but a few more options would be nice. Changing the weapon systems to allowing player options for both sides would be great ala the Hornet/War Walker. Supersonic wouldn't go amiss either but should probably be left to the smaller of the Eldar vehicles (though the Warp Hunter did get it IIRC). A decrease in the points for the more expensive weapons (EML, Bright Lance, Starcannon) is of course an expected outcome though the chassis here isn't really that expensive for Eldar considering what you get - a slight reduction or improvement to BS4 (this seems to be the norm for the rest of the new Eldar vehicles from Imperial Armor) could go a long way.
Improved vehicle upgrades would also be nice and not having to pay through the nose for some (Holo-fields for example though this would only get a slight reduction if any). I again imagine Spirit Stones being similar to what they were in 3rd edition now that we have Living Metal & Fortitude but something to allow them to re-roll terrain checks (or ignore them), improve tank shocks, etc. would be appreciated.
Otherwise not much needs to be done - it's a gun platform which can carry units which is going to make it always a favorite amongst players who desire flexibility. It may not have the raw killing power of a Warp Hunter but it makes up for that with other options. Perhaps allowing it to be taken as a dedicated transport in some instances (ala Battlewagon, Land Raider, etc.) could also free up list building opportunities? This is less likely though if the Vyper gets moved to a Venom-like transport.
The Falcon is a gunboat with the most heavy weapon points for an Eldar army, with the standard speed of Eldar vehicles. Aka pretty good fire support. It also has transport capacity and although this is vastly underused due to the lack of good Eldar units and the way 5th edition works, it gives the Falcon that extra nudge of goodness, particularly when you add a couple upgrades to make it very durable. Who doesn't like a durable transport protecting your Troops?
In normal Eldar armies (no Imperial Armor), there is little competition for the Falcon. Fire Prisms & Night Spinners are the top two and if you're looking for pure firepower, they all have their extra merits. The one downside for the Falcon at this point is they are 33% more expensive than their counterparts and even with the added transport capacity bonus, this is generally too much to justify. It can be done but you'll generally see a Falcon + two other combo (particularly Fire Prisms since they work well in pairs) than the three Falcons of old.