A lot of adventures seem great, but are flawed in play. This can be an obvious flaw like Lost City of Gaxmoor's CR 20 BBEG in an adventure for 10th level PCs. It can be more subtle - B5 Horror on the Hill is beautifully designed but an absolute meatgrinder, too much for my group even using 3rd level 3e PCs -it was supposedly written for 1st level BECMI PCs! B7 Rahasia was overall very good but I had to greatly simplify the end section, and a bone golem was a bit much for 1st-2nd level PCs.
I enjoyed the C&C DCC Palace of Shadows a lot; it suffered a bit from being sketchy in places, the final battle has no room description. Typical DCC lack of editing I guess, but still very good. Lost City of Barakus is extremely robust, 30+ sessions of play, let down by an underwhelming finale battle - blame 3e's overpowered spellcasters, the lich got Scorching Blasted to death in one attack! Vault of Larin Karr is an excellent sandbox, after reducing the map scale to 1/5 the art is the only thing I dislike about it.
All the 4e modules I've seen have been pretty atrocious. I like Dungeon Delve but I'm not sure it counts.
I enjoyed the C&C DCC Palace of Shadows a lot; it suffered a bit from being sketchy in places, the final battle has no room description. Typical DCC lack of editing I guess, but still very good. Lost City of Barakus is extremely robust, 30+ sessions of play, let down by an underwhelming finale battle - blame 3e's overpowered spellcasters, the lich got Scorching Blasted to death in one attack! Vault of Larin Karr is an excellent sandbox, after reducing the map scale to 1/5 the art is the only thing I dislike about it.
All the 4e modules I've seen have been pretty atrocious. I like Dungeon Delve but I'm not sure it counts.