Hmm., when was the AI overhaul exactly? I compiled just a few days ago.
I recently boarded a crashed very large UFO (a battleship I believe it is called), with 3 intact power sources =).
The sectoids were quite vicious when fighting, though still had no change against my troops. *But*, they never ever even tried to use psionics, which could have helped them a little - byt just my thought maybe it's an oversight in the new AI? Or, maybe by chance, my soldiers just happened to be resistant, and the sectoids noticed it and gave up. Poor sectoids, I almost feel like I shuold not have killed them. Maybe I'll go pacifist in the next game ;-)
Need to retest with the most recent GIT I guess...