The only area that is laggy for me is the engine room(~40fps). I get my max fps everywhere else in the map(76).
It would be a really good idea to merge and caulk the engines. Several sections of it are formed out of a half dozen brushes when less could be used, and there doesn't seem to be any caulk used on the unseen surfaces. It would help to make the perform a bit better.
Aside from that, the bright yellow and red pipes feel really strange. They look like they should be giving off light but they aren't. Just making them a plain yellow/red colour rather than a non-lightmapped shader would go a long way. Also, you overuse the cyb0rpipes texture in the engine room, especially on the ceiling, but also the floor. I think it would be a good idea to break up the pattern with another less busy texture.
The computer model you use is fullbright. To fix that, add either spawnflags 4 or 6 to it I think. Also, the room with the computer is way too plain. Pipes, crates, hoses, or any sort of filler decoration would be welcome