I have the first Drizzt trilogy but have only ever read Homeland. I quite enjoyed it, like you, but wasn't sure if I liked it enough to read the others. I do intend to go back to it, though, so I can always send them to you when I've finished them.
From what I remember, I agree that it's not as claustrophobic-feeling as one would expect, although I attributed that to the fact that it's told from a Drow's perspective and he'd be more or less used to the enclosed space. I was definitely a bit disappointed with their foray into the tunnels (is it called the Underdark? Or is that just NWN?) - it was distinctly less terrifying than expected.