Jeremy Condit's net maps (4 of 'em), converted from M1 and enhanced. These were great levels for M1 (usually with some sort of unusual twist), and he's really improved the feel of them for M2. Stop the Press!, for example, doesn't feel so claustrophobic anymore, now that the outer ring is outdoors... These are all worth a look. And read the readme... there's quite a bit of useful information there. Update fixes a bug, and adjusts ammo...