Nice map dude. I support the idea to turn down the lights a bit. I dont know the original map but for half-life deathmatch I feel a little claustrophobic all the time. IMHO you could give a little space here and there, maybe increasing the roomsizes. Ah, and the ammo_gaussclip on top of the vending machine is unreachable for me. Maybe put it little closer to the edge?
When running through the map I get stuck very often at the many edges in the corridors. You could flatten them with clip brushes or triangles so they push you away from the edge when getting close.