I have the Super Adventure. It is based on the assumption the 1E and 2E versions of the adventure happened in times past, and now Acerak is up to a new plan which the PCs must stop.
It is four adventures connected by the common theme of Acerak's plans. They play out between levels 10-22, with the DM putting adventures of his own design between the pieces.
The Garden of Graves (Level 10) takes the PCs into the Feywild to a set of Fae caerns.
The Tomb of Shadows (Level 14) takes them to the ruins of Moil in the Shadowfell.
Skull City (Level 18) takes them to Skull City and the original Tomb of Horrors.
Dead Gods Tomb (Level 22) takes them to the Astral Sea and the final confrontation with Acerak.
Some traps and tricks are explicitly set up to test Player ingenuity rather than simply skill levels. There are some pretty nifty puzzles and traps and some interesting fights and critters.
I'm most of the way through it and pretty pleased. (Interestingly, you could easily interleave this with Revenge of the Giants, especially since ROG has a time travel segment where you meet Acerak.)