I got the tank at a 70% discount (20% more than what I was aiming for) and played for a bit, so written below are my first impressions/ review. I'll compare it to the T26E5 since it's the American premium HT to get (why would you get a T34 lmao just play the T29 a tier lower)
Let's take a look at the tank trifecta of criteria: Mobility
The mobility on the tank is good for a heavy, only decent overall. You're rarely going to hit your top speed of 45 and just hover around the 40 mark. Turning kills any speed on this tank because of the terrain resistances so it's best to take racing lines everywhere you go to minimize the speed bleeding. Overall a touch better than the T26E5. 3/5
Firepower
This is the highlight of the tank, honestly. It's such a good gun I believe it should be on a tier 9 (it should've been ). Because you don't move so quickly the bloom on hull movement does barely anything for the gun and coupled with the really good but not IS-3 tier .1 turret dispersion means you snap for days. The below-average aimtime is not a problem because the bloom is just so low. The alpha and reload sit at a very good sweet spot wherein you can trade decently with heavies and also out-DPM them 8/10, which fixes my problem with the T26E5 wherein the alpha and bloom are hard to manage to fight decently with the enemies. The penetration is also pretty good, although you'll have problems fighting tier 10 superheavies but all tier 8s have problems with those anyway.
The only downside I can think of is that you'll get out-traded by most heavies, especially so with the Defender/VK 100.01, which is really important in heavy brawling where you both trade around cover one at a time. 4.5/5
Armor/Survivability
You're honestly not going to bounce anything except with the turret. The hull armor is just garbo enough that anything tier 7 and above will autopen it. You'll have to bait with the tracks to bounce anything on the hull or snapshot your trade so they don't get a chance to hit you (which you're really good at). Turret wise, it will bounce most shots save lucky cheek shots. The cupola is very prominent, but if you're playing it right you can make it a hard shot for most of the enemy. It just means you can't stand still or you'll get hit in the cupola. The height is a problem since the hull is kinda tall, so you have to pick the cover you'll use. Arty wise you're going to get splashed by 200-400 every hit which isn't ideal, especially since the tank is pretty large. I've also noticed my crew dying a bit more than usual, so you might want to consider a large health kit. This the only category wherein the T26E5 edges it out, if only because the hull/turret combo is more useful.
View range is also really good for an 8, so you can at least spot in high-tier games where you're kinda useless. I run optics on the tank although a case can be made for vents if your crew is good enough and/or running food. 3.5/5
How is it as a premium?
Since you can do a lot of damage due to the really good gun, you can potentially make a lot of money. It's not a 90mm shell though in terms of cost/damage, nor can it farm high-tier opponents like the S1/Lowe, but it makes good credits. Should I buy it?
This one's tough to say, especially since it's only a marathon tank for now. At 10-40% discount I'd think about it, 50-70% discount I'd say buy, 80-90% is too good of a deal unless you don't want to give WG money. I got it not only because it was 70% off, but also because I like collecting historical American tanks. I'm still kinda miffed they renamed it to the M54 since it never made it past prototype stages. As a crew trainer it trains both the T57 and T110E5, but the American HT line in general isn't in a very good spot these days bar the T29.
Totalling up the ZXScore™ and the tank comes out at 11/15. It's a really good heavy, but it's no Defender :^)
thank you for reading my blogpost Addenum: The HE does 440 damage, so you can splash low-HP tanks and kill them. I still wouldn't rely on it, though.
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I'm not sure why you're looking at UFP effectiveness, especially since nobody in their right mind would shoot an UFP unless they're a.) braindead which is easy to outplay or b.) they have enough pen to butter it, which is most tanks you're gonna face. Tier 8 is a very popular tier, which means most of the people you fight can instapen the hull.