I've played the compatible Castle Ravenloft D&D Boardgame that use the same core mechanics. The rules aren't too bad, actually- just a tad more than HeroQuest. It works more like an adventure scenario machine, and you can get it running quickly. Our first game took about 2 hours...not bad.
If you're interested in getting the run-down on the Legend of Drizzt D&D Boardgame, check out the WotC
tutorial video (about 13 min. long).
Lacking a Zargon role, it doesn't reach as close to true dungeon crawling as HeroQuest does, however. It's a slightly different animal that abstracts certain elements to provide a tight gameplay experience. What it does do, it does well: provide a gateway dungeon boardgame for the market of today, just as HeroQuest did in the past.
Being satisfied with HeroQuest, there's no need to look further, but... if you get a chance to sit in on a game, then do it. The tactics can be engaging, and you might even get caught up in the adventure 'story', as with HeroQuest.