Cool, just a few points on the proto airex map:
1. The yellow sand texture looks out of place on the catwalks. I would replace it with a darker brown mud or dirt texture to stop it from clashing.
2. Make sure that all exterior walls are nodraw'd
3. Nodraw the grate brush on the side that the player cannot enter
4. Fix the black texture (might just be my beta)
That's basically it, other than that it's cool. Good job man.