http://img239.exs.cx/img239/5803/dmdepotrc2previewtitle7uz.jpg
If anyone is still playing HL2DM, check this map out. It's pure class. I just had a nice 12FFA on a French server, and I had no problems with lag at all. The map is quite stunning to set foot in -- not because of any specific design or set piece, but because the sense of place is so flawlessly realized. Not that it is devoid of fancy setpieces though. (it even has a very nicely done moving train)
It's very large, so you'd probably want to find a server with at least 6-7 people on it. The only knock on the map I have is that more areas should have been clipped off -- you can jam yourself in some tiny/awkward places (though you won't get stuck, it just sucks moving around in it)
Anyway, yeah, this map is pure fun. Go find a server!