I've played your map and I actually think it has a lot of potential, but you have a lot of work to do still.
Textures are really repetitive, try to vary them, add detail in the borders of everything, especially stairs that have the same texture as the floor, you should give them some border texture, and make 'em a little larger, (1x1 isn't really good for deathmatch). Those huge pipes could use other texture as well, ceramic isn't suitable for pipes :\.
Apart from that, you should add more detail and some more lights, it's pretty dark in there.
Try those things if you wish. Good work.