This problem carried over from the original EaW, and its a bit frustrating.
Whenever I play as the ZC or Empire, the Rebellion "mysteriously" reaches Tech 5 in an instant. By Day 5 the AI is raiding my planets with Garm Bel Iblis and attacking my stations with B-Wings and Ackbar.
Changing the difficulty doesn't seem to be doing anything, aside from the length of the attack and how much force he's using.
In addition to this, the AI for the Empire and Rebellion both never use Imperial Star Destroyers or Mon Calamari Cruisers (aside from the heroes), though the ZC uses its capital ships plenty.
I see others have the second problem I named, but I don't see anything on the first.
I like a good challenge from the AI, but not at the expense of cheating.