I played the original extensively and have to say this is every bit as good!
I'm not totally convinced that they haven't nerfed the difficulty slighly but I'm playing on hard and that seems to balance it out nicely.
The new items are nice, they could have put in the murderous sword of killing +999, and ruined the game but they thankfully didn't.
I've nearly finished the game now and can honestly say this is just as good as ever. The storyline is epic. It is damn hard to play evil in this game though.
There's a lot of reviews on here that say "don't buy this game unless you played the original", but it's not THAT hard, it's turn based when you want it to be. Just mash quick save a lot so you can try different tactics on a hard encounter. I wouldn't recommend having your character as a mage first time round as assasins (there's always some hired goon after you) etc tend to go for your main character even if you have them further down the running order.
I still think this is the closest computer game to proper DnD, and I like how you can turn on hit rolls. Ultimately, I can't wait to play BG2 next (again) as that really is ADnD but with a macastic sadist for dungeon master.
The visuals might look dated to some, but I find it endearing really, although I would have thought they might work on the audio a little as it's bugged to buggery. Compatability wise, I'm playing on a crappy toshiba windows 8 laptop and it runs perfectly.
Finally, the added "pits" mode is great, so much fun trying to make silly parties and seeing if you can do it, ie- 6 mages haha.
Dialogue/ characters 10/10
value for money 10/10