Woot, variant discussion, I will respond to the ones I either disagree with or have a comment on the weapons as a whole:
Owens B: If this were the last patch i would agree, but if used correctly the refire on the SRMs is now so quick you can chew up light mechs and let the Owens' armor do the rest. I will agree that it is not an easy ride though, you have to angle the SRMs correctly so that they don't miss and manage the lack of torso twist.
Raven A: You are way too harsh on this design, I will agree the TAG is useless but as an early game brawler, particularly on marshes its a fine machine. While the Osiris does have more firepower and is just as fast if not faster AND has the torso twist, its the shape of the Raven that gives it the advantage. The sleek design distributes the damage far better than the round nosed Osiris and the weapons are far harder to hit aswell. Jump jets are a moot point on a mech that light that early in the game, at anything but the longest ranges you will get hit back, and hit back hard as you have none of the weaving speed. Its a great mech against early mechs that bank on one large weapon, just destroy the weapon while you weave around.
Puma: While I mostly agree with your assessment here I just want to comment on how disappointing the Puma is over all at attacking, its lack of torso twist and barn-wide backside make it a death sentence in brawling, even though the Puma C is the best component destroyer in the field barring the assaults even with the MASC and ECM on board its useless trying to sneak around with it. As for the Prime, its a good design but I don't like flamers overall and its only good for sniping, good mid and early game damage but the squaty design is disastrous for trying to peak over hills and fire the ERPPCS.
Cougar, Awesome Nova: With all due respect I think you short changed the PPC/Laser combos because you have trouble with them, the PPCs outrange the lasers and allow you to stun targets before getting the majority of damage with the lasers. And BA's are farrrrrrrrrr easier to kill with PPCs than Lasers, its a good compromise IMO.
Bushwhacker: oh bushy... oh bushy bushy bushy... One of my favorite mechs to use yet such a load of fail as of now. The Prime I think is a lost cause, similar weight on LRM5s is what... SRM2s? Useless. And you really cant buff the AC10 without it directly buffing the UAC10. It is so slow that JJ's would but sort of useless and MASC too annoying to keep up with. RAC's are a joke now against anything but areo which is already struggling as it is. Don't know what todo on this one. Don't get me wrong though, I use it anyways cause I love using it.
Shadow Cat: Mostly agree but it is easier to destroy the UAC20 than most people think, once that is gone it is usless. I prefer Prime but agree its a solid mech over all.
Catapult: Prime is not garbage. It has far more survival capability than the vulture and even comparing it to the Cougar is a joke, in missile combat, armor, especially component armor, is key if you want to gain any ground while boating, the launchers are out of the way rather than the vulture's which are easy to destroy.
Warhammer: Correct me here but I thought this was significantly cheaper than the Thanatos? Anyways, the Prime is in many cases better than the ERPPC variant because it allows the pulse lasers to constantly fire without fear of over heating.
Thanatos A: this variant is ownage yes, but I almost can't use it because of how fast it runs out of Hgauss ammo even when you get an extra ton, as a brawler you dont have the option to go back to base every ten seconds and the Than is slow anyways.
Vulture: Prime is superior to missile boat hands down unless you are sitting on a hill pressing a big red button and getting kills as you say. SRM variant is overrated, sure its got great firepower, but the vulture is not a brawler, something that lightly armored and that slow makes it an easy target if you have any backpedal speed what so ever, more of a gimmick mech like the beatstick IMO.
Gauss variant, boring to pilot, boring to fight, I didn't mind it before, but now as its the cheapest Vulture its spammed too often, all aboard the yawn boat!

Atlas: Almost a joke sometimes, if it had the old MW4 hit boxes where it wasn't so easy to head snipe that would fix half the problem, I agree the UAC version is the best. Heavy Gauss Variant isnt too bad either.
Mauler: I really do not agree with the direction they have taken the small caliber AC's and the RAC's. The Mauler prime was one of my favorite mechs, used it constantly in MW4, it depresses me how useless it is now, the Mauler cannot look up far enough to be good AA and the AC2 damage on everything else is a joke, a shame really. ELRM15 variant fails, it runs out of ammo even faster than the normal LRM15 variants.
Hollander: I think you slightly underestimate the prime, in BA heavy environments you are completely fncked if you decide to take the heavy variant. And I'm not talking about Extremity, taking a Hollander at all there is laughable.
Oh and, Flamers<Mguns at taking out BA's.