I've been playing D&D for 17 years (yes, that's right, seventeen years. . .jeez, has it been that long?), and this was the first module we played, and since then I've played it a few more times as both PC and DM, and it still never loses it's flair. The 25th Anniversary issue is even better! More detail to the Keep and its inhabitants, a very interseting group of NPC's to chose from to join the party (if you so decide), and you even get the chance to join forces with a tribe of humanoids to drive away the evil clerics! I love it! The only reason why this got four stars instead of five is because the original was in the Mystara campaign (my personal favorite), and they try to push this gem into the overrated Greyhawk world. . .still, newcomers will love this because of all the special instructions at the beginning, and old-timers like myself will get a kick out of the nostalgia factor alone. It's not exactly the same as the first, don't get me wrong! There are quite a few little surprises that will make you say "Hey, that wasn't in the original!", and it's all good.
Well, e'nuf said! If you want the advice of an old school gamer, this one is worth the money.