I think its baffling that the game gets props for its AI. Its not strong enough to challenge a skilled player in the slightest without substantial cheating. Many of the things that are wrong with the AI are ridiculous, like building too many embassies. Yeah, yeah programming AI is really hard...but come on, tons of embassies can't be that hard to fix and you can't call it great AI if the planetary builds are so messed up.
The AI does do a reasonable job with the initial colony rush...but has *terrible* follow-up if colonies are out of the reach of its standard colonizers...that PQ 26 planet will be sitting just the tinniest bit beyond the range of its colonizers and it will give you *tons* of time to steal it.
Many of the AI's want to have a military lead...but they ignore planetary invasion for a *long* time. So they spend money maintaining a fleet that has basically 0 intimidation value.
I find "painful" to be pretty easy...at least so far. Got to move up another notch in AI I guess.