Everyone compares this game to Baldur's Gate... And that's of course not without reason, Icewind Dale is based on Bioware's Infinity Engine, just like Baldur's Gate, and on the surface it looks and plays almost identically. But Icewind Dale is a rather different at heart... In short, I would say that, Icewind Dale is more open-ended in terms of what you make your experience playing it into. And that's not a result of it being non-linear but because Icewind Dale lets you create your entire party and thus the game pretty much leaves what goes on inside your party to your own imagination. That way Icewind Dale has you acting all the lead parts out as you take your party, entirely made out of your own unique characters, through the quests and battles that the still quite engaging story leads you through. And while the game essentially leaves your party all up to you, it's still a really atmospheric game, with great artwork and soundtrack. As you travel through the icy north, you almost feel the cold. All in all, I would say it is a great game on it's own merit, and it may be more fair not to use Baldur's Gate as the baseline all of the time and just go with it!
