IMO remove the AC-130 from Rush altogether. If the teams are even its hard enough defending when theres just a few tanks etc to worry about. It's almost impossible if you have to worry about taking down a AC-130 and people paradropping in from every angle.
You cant push up as a defensive unit, you end up completely disjointed. Thats what I love about Rush, two teams head to head, attack and defence. Work as a team and you'll win. You cant group up with the AC-130 else you'll all die.
I've played on both PC and Xbox, it's easier on PC because theres generally more players, but on Xbox its tough because it's only 12 vs 12, and you need atleast 2-3 with Stingers to take out the AC-130, plus another guy is normally in the plane so that leaves about 8 players defending two MCOMs, then when the AC-130 kills a few of them its just an impossible task.
I would even be semi happy with the Paradrop being disabled... I've seen MCOM's being planted before the defending team can even get to them.