VIAVGA DM2, created with Doom Edit, is claimed to have consistent playable frame rates and a higher level of detail.
The map uses Doom 3 assets as well as customised light and decal textures, with the map connecting several large combat zones and stairwells.
Lots of stuff is littered around the corridors for people to pick up - Via said it's suitable for so-called free for all players up to eight, as well as team death match games.
The zip can be downloaded from here. ยต