So of late, these have been on my mind. I've often toyed with the thought of chucking them into lists en masse, particularly if there are ~30 points leftover, and we've seen quite a few authors do this before (and currently) but I think after another set of games where I've found terrain is really affecting my vehicle movement, it's time to consider them. At five points a pop for most Marine armies, for the most part they are a nice upgrade to ensure your vehicles aren't being fudgemuffined 1/6th of the time by terrain (changing it to roughly 1/36).
This point cost has a sort of inverse relationship with use however. The less vehicles you have, well the less important this upgrade is but the cheaper it is for your army. When you have six or eight Razorbacks/Rhinos/Chimeras/whatever moving forward however, well the upgrade becomes more important and starts taking a fair chunk of your points. Why is it more important? You're not going to have room to put all the vehicles where you want without going into at least some terrain. Dozer blades let you do this with much more confidence as the chances of your vehicles getting stuck are a lot slimmer.
This is a huge improvement as you're able to move more confidently with your vehicles and this impacts everything within the game. Movement is important and it's generally how the best generals differentiate themselves from each other and taking the majority of the randomness out for five points per tank is a very nice option indeed. This opens more of the board and limits some of the weaknesses mass tanks has where they end up blocking each other whilst fighting for the finite space available. This is even before the enemy takes a hand and starts using said space as well (blocking) or causing damage to your vehicles. A simple stunned result followed by a lead tank immobilising itself on terrain can cockblock an entire army. Five points to make this happen far, far less often? Pretty good good buy in that sense and opponent's limiting your movement through terrain becomes a much less dangerous proposition. It's not fool-proof but if you have an army of eight+ tanks moving through terrain each turn, the averages are in your favor for not immobilising half of them by the game's end.
The question becomes, if you decide to take dozer blades, which tanks deserve it the most and how many should I be giving my army? In reality, you don't need every tank to have one. Tanks like Predators or Hydras in the backfield are rarely going to need to push their way through terrain and when they do, their ranged guns still put them in a good position to impact the game. If you have extra, extra points left over, it might not be a bad idea but they certainly aren't your priority. Your priority is any tanks moving forward or around in midfield. This is where movement is really important and will define who can win or lose games so obviously investing those points on those vehicles is going to lead to the most benefit. Even here though, you don't need every tank to have dozer blades as you can manage which tanks need to go through terrain and which don't (or do to a lesser extent). The security blanket for allowing this on all tanks though? For five points? Well if you have the points spare, do it and if not you'd be looking to get at least two-thirds of your forward moving tanks dozer blades. For most Marine armies this is going to cost around 30 points, so nothing too huge though Imperial Guard with their 10 point dozer blades are going to feel the pinch more.
Most armies will have to lose something to gain these upgrades though unless they have had points lying around. Whether it's something like a couple special weapon upgrades or squad members, the end result is going to be less firepower more often than not (but not by a significant margin). However, by making your parking lot more reliable in enacting it's movement, the firepower you do have is going to be more accessible and the army's battleplan is less likely to come to a grinding halt when that solitary one rears its head. It's certainly not fool-proof and not a necessity, but having had this happen to me numerous times, it's a good investment of points without completely changing an army list around.
