As for the advantages of power armor as a platform for heavy weapons, from what I've seen of the 40K universe, there are a lot of examples where it's an advantage.  A weapon that needs a power pack, for example, can be instead hooked to the Powerarmor.  A powerfist is especially difficult to use without power armor, for a specific example.  Carrying, say, a man-portable heavy laser (which needs a power pack) would be much easier while buffed by a suit of power armor.  The weight of the laser and it's pack would slow a non-augmented person down significantly... and usually you'd solve that problem by having a second person carry the power pack... but with a suit of power armor, you could bypass that problem.<br/><br/>Yeah, carrying what is normally a tripod mounted, two man weapon by yourself is a bit silly... but not for a strong man in heavy power armor!  It's the basic difference between a Space Marine and your basic infantry grunt... the space marine carries more firepower, and shrugs off small arms fire.<br/><br/>I'll tell you what, I've come across whole gaming groups that thought that heavy armor in a high tech game is just a bad idea... and if you use it wrong, it certainly is... but it's out there for a reason, and power-gaming aside, I like the idea of it.  If TGT agrees to let me play, I AM getting a set of power armor and at least one heavy weapon.  If that gets me killed...?  Well, it'd make for an interesting scene, at the least.<br/><br/>I don't know the game mechanics for this system, so obviously I could be making a big mistake there... but let's pretend that character concept trumps power gaming for once, and pretend that power armor could possibly be as useful as the people who built it for millions of space marines thought it would be... if used right.  There is a reason why one of the most iconic images of Warhammer 40k is of a Space Marine in full armor, holding a ridiculously huge gun with a chainsaw bayonet (or some other equally silly weapon) attached...  it's just... so... cool!