Geeel: I've been playing a lot of (mod laden) BG1 the last few weeks, so I've been curious about BGEE and picked it up on Steam this morning.
I have a friend who's played a lot of BGEE and hasn't had bug issues, so bad bugs may just have been an old version of BGEE.
According to the developers, what happened was that their contract called for it to only be sold their store (beamdog), except then suddenly atari put an alpha version on steam (full of bugs that were fixed in latest version) and falsely claiming it was the final version. And pointed out at some fine print they missed that allowed them to do that.
Then atari's legal department ordered beamdog to stop selling it through their store and apple store so now it can only be sold through atari's own channels (their store and steam), where atari gets all the money and they get none. As a result they stopped development (mid patch I might add). They seriously suck at reading contracts... then again, atari is a bunch of morons too who are scaring off any future potential business partner
That all being said, even the so called "finished" version had a lot of new bugs introduced. Didn't really improve the game in a worthwhile manner, focused on porting it to tablets for some insane reason instead of properly upgrading the game (although they are contractually not ALLOWED to make changes to the core game, only make DLCs for it... again, total messup on their legal team's part).
The whole thing is a sad pathetic joke that isn't worth anyone's time. Get BG1+BG2 on gog and install trilogy which combines them into a single game; and also adds dialog to provide proper continuity in case you finished BG1 with an alignment or party other than what is assumed... the assumed is a good party composed of you, Imoen, Khalid, Jaheira, Minsc, and Dynaheir.