It's a good start. As mentioned, the lighting in the halls is way too bright in relation to the rest of the map. Also, there is an area in the ceiling of the human base that is noclipped.
As cool as it may be, I think it would be wise to block off the glass between human and alien base in order to get good vis seperation. The human base is usually laggy enough as it is without it looking into a foggy alien base. Your map would perform a lot better if you did that, at not too much of an aesthetic cost. I notice you're a chronic bad optimizer, too; Outpost p4 and The Two Towers are both interesting maps, but they both suffer from the fact that you can't seem to accept the limitations of the q3 engine.