Hi there.
Here is the opinion of a novice who has gone through BG1 and BG2 just once.
BGII was my first RPG and AD&D as well. No idea how one was supposed to play a game of that sort, not to mention clever choices and tactics allowing you to win without taking much pain (okay, you can stop smiling now). However ignorant I was, I proceed fairly satisfactory for a novice, and after trial and error managed to finish the game. I was surprised and overwhelmed; I found myself being definitely addicted to BG, but there had been many gaps in my knowledge of the events preceded BG2 and all the literature of my own past. And here comes BG1, which I have just finished –at last!
I’m quite sure that BG2 is a more subtle and complete game in many aspects. NPC’s, for one, are more interesting, mature, and therefore appealing, feeling like real individuals: each one lifts the burden of his/her own past, of which you are aware of, and that’s a big difference from BG1; in other words, they are round characters. Even Minsc’s voice has lost its previous heavy and kind of “slouchy” tone –anyone noticed?
Dragon battles? Ah, I think they are superb! You have to think and plan carefully if you want to stay on your feet and win. Even the battle music sounds so epic and inspiring that I could go back for just fighting the dragons and only. (Even the music of BG2 is much much better than that of BG1.)
And what about those nasty Liches (Shangalar and Kangaxx come to mind) or the terribly annoying Mind Flayers, or even the freaking vampires? How can they be compared to all the Kobolds and Ogres of BG1?
As for the wild areas, my only problem is the slow movement of my party. Toooo slow (*yawn*). Even with the Boots of Speed you feel that the wearer is going just a bit faster than the rest of your party. No comparison with BG2.
Bag of holdings, scroll cases and potion bags came too late, I think. What about all these stuff we were forced to leave behind us in Durlag’s Tower –as we were trying to mark our passage for a safe coming back? Even for those of us who had originally bought BG2 without the expansion pack, the stocking of goodies had been a nightmare there, too.
What I think stands out in BG1 is the story line and the intrigue of the plot. It’s more real and touching, even for a Bhaal spawn like myself

Saverok is an original dark, mean figure that you have to deal with eventually. John Irenicus, on the other hand, wasn't that impressive. Just a lunatic whom you had to fight. Even Bodhi was more genuine and more challenging for that matter.
Durlag’s Tower and Watcher's Keep are both monumentally difficult, and hold a real challenge for any gamer who respects him/herself and wants his/her powers and abilities tested.
Coran is still one of my favourite NPC’s. When in Durlag’s Tower I had him leading the party, he said, “I think my new responsibility will be a great deal of fun.” And a few seconds later, “Luck is always on the side of the romantic.” (!?) Kalessia, in Iron Throne headquarters is quite funny: “Touch me not… You are unclean.”
Concluding, I'd say that BG2 is better developed and advanced than BG1. So far I’ve loved both games, but I wouldn't say no to a combination of both games' virtues in a single one
P.S. Any ideas where has the Saverok's essence descended to? What was that hall full of statues?
Cheers,
Aubrey