my first impression with the limited experience i have had with the weight system has been positive. I really like how you can't just throw everything on a LT now. It certainly makes the LT less of a threat, and it actually give meaning to heavies, instead of us being able to dominate the whole game with LTs. My primary concern is whether the AFV has been suitably balanced as well. Lord knows, THAT didn't need any nerfing AT ALL. APCs might be a too strong, right now. A new tactic that has developed with startling success is the heavy APC rush, many APCs with HMGs. I don't think this is in keeping with the flavor of the game of the intended use of the APC. Possible, off the top of my head solution: I think lower the weight of the APC just a little... JUST a little, so that if you want big-ass guns, you can't put on as much armor. I haven't had time to study weight systems and weapon values so I don't know how practical this is.
APC with heavy guns: only APC has 3 mg slots so it's fair. I think that person that gave APC these slots knew the consequences. I just don't like this enormous bio/ap/he/plasma mg stalling effect. If you could go for APC attack and second side for normal research path (armor, engine, med, HE) it should be just balanced.