Mine ran OK (BG1 + Tutu + Widescreen + Larger fonts; BG2 + Infinity Cracker + Widescreen + Larger fonts) but I could feel the mouse pointer stutter a little bit, which didn't happen way back then in my 1 GHz Pentium 3. I remember the game crashing a couple of times but it could be normal. These were disc versions of both games. I have them on GOG as well but haven't actually tried those.Hmm I didn't have a single issue with modded BG1+2 from gog. The EEs on the other hand are said to have added more bugs than features and new content is often perceived as mediocre, if that. The one big upside I see is that these games (hopefully) get some more attention among a new generation of gamers influencing the industry as a whole.
One thing that bothers me a little is how tiny everything looks in larger resolutions. The enhanced editions let you zoom in but from what I've seen it is not a very high quality, looks all blurred.