I took out a bank loan to buy my original laptop when this game originally came out. The game was a little clunky WAAAYYY back in, and the EE version for this is an across the board improvement. For many years I preferred playing BG2 over BG1 because of the improvements that BG2 had made when freshly released. BG1 now has a great experience. And thanks GOG for allowing me to play one character over a number of devices so I don't have to restart games.
This does add a lot of content, and the AI is often better. However, it does get glitchy, like spell book updates don't stick, AI turns off on its own, music and sounds sometimes disappear. Still fun with new content, it's just the original CD-ROM version with the occasional patch didn't feel this glitchy.