1. It seems as if AA weaponry has been shifted from overpowered in 2.0 to even more underpowered than 1.0 AA. It's probably a combination of reducing the damage multipliers on 'light' armors for AC's and MG's and increasing aircraft armor, but as a Harasser C emptying a full clip of 800x2 MG bullets on a Sulla will not take it down (assuming 45% of the bullets would hit), whereas in 1.0 it would take about 1/2 a magazine, 1/3 if your aim was good or they were flying directly at you. My sample size is approx. 8 matches piloting a Harasser vs. aircraft. (can't say much about the AC/5 and RAC/2 as I have not tested those).
2. BA micro heavy laser is off the hook. I'd compare it almost to 1.0 LPLs in terms of relative strength to other weapons in its class (the other BA weaponry). I love that it's a dedicated BA weapon and it's really that weapon alone that makes BA right now a serious threat, but as it stands a match could be won solely by having a team spawn as BA and swarming enemy mechs. Who cares if they get picked off? the cash you earn from killing a BA (even more than one) doesn't equal the amount of money/score a group of BA gets from downing even a light mech. Then the other team starts doing it and before you know it you're playing Starsiege Tribes. Now all we need are BA Spinfusors and Mortars... I don't know how I would fix this one, it almost seems like nerfing this even slightly will decrease significantly the appeal of BA.
3. Going under the water in Thunder Rift, it becomes pitch black. You can't see where you're going at all and it is frustrating to climb out of if you end up on the lower level. This level is beautiful otherwise, if only this issue could be fixed.
I can't think of two others at the moment. They would probably end up being whining about game balance (besides the two I mentioned above, which I feel are legitimate gripes), but it's probably because I was very good at piloting mechs and aircraft in 2.0 and with this new paradigm I feel like I'm starting as a newbie all over again. But I accept that it is part of the balancing process and I'm sure that with practice I will regain the level of skill that I had before. This is a wonderful mod.