I wish it were easier to unlock the alternate weapons for each class. The prices are pretty steep, 100,000 EXP for the second weapon iirc.
Another incentive to pay them real cash monies I guess.
And curse you infiltrators. Those are the guys I'm always dealing with back at base, attempting to keep the generator online whilst these guys pop in every 50 repair units. Easily dealt with when you're a Juggernaut (or Doombringer, but not so much due to no area effect weapons) unless there's more than just an infiltrator down there...
I once had to deal with a team of 2 infiltrators and 1 juggernaut who kept coming back again and again and again no matter how many times I cleaned them out and repaired the generator...