you gotta love those env_cubemaps!!! and yeh i think the best bit about hl2dm is the fact that you can shoot with gravity gun! and whats funny is that you can shoot say explosive barrels at people!
noobs sometimes hold explosive cans in front of them with gravity gun and most people just shoot the can in front of him so he died
there will be great maps to come from people (cough rabid) which will use the physics well he he (shooting a wooden support and the roof falls down)
The cool thing on dm_lockdown is that theres a plug on the floor which you can pick upwith gravity gun and place in the socket near it! This triggers the fan in the vent to go on and kills anyone inside the vent!
Inside the vent are rpgs and ammo so thats why people go in there