My initial impressions:
The AI skill is about right, at least for me. I'm not the best combat pilot but not the worst either. The only NPCs that are now instant laser-fodder are ones that are far enough below my combat rank that they count zero towards any progression. Tactically speaking, the rest seem to pose a reasonable sliding scale of threat as their rank increases to the point that taking on an Elite opponent in a ship of equivalent capabilities to one's own most definitely makes the player the underdog. That's a good thing.
I was a little perturbed by the spawn rate of the higher ranks. Seemed a little skewed to me. I recruited a friend who is a new player and kibitzed over his shoulder, seemed a bit skewed there too, in about the same proportions so it didn't seem to be due to my higher rank. (not that it should be - At higher ranks only higher ranks will take you on and interdict you, but HOW OFTEN that higher rank shows up shouldn't change. Just because I rank up doesn't magically change the entire population of pilots in the galaxy)
The thing that really bugged me, though, was the prevalence of engineer buffs in the mid-to-high ranks of NPCs. We've got this small band of eccentric geniuses, picky about who they work with. Suspending disbelief to the point of accepting that all of these NPCs, who don't even have the cachet of Pilots Federation membership to recommend them, were supplied with all of these shinies seems a bit much. Given how much effort WE have to put in to get a decent mod from an engineer, the fact that NPCs seem to be able to pick them up at the local convenience store is a bit irritating.