General comments:
- It's an interesting theme, but don't make it MANN CO. MANN CO is and will always be a very neutral facility, so don't make one team own it or it will simply be contradictory with TF2's story as we know it.
- Your metal pots looks good, but that's some crazy yellow liquid you have. In general, molten metals are much more whitish with an orangish glow:
- You have a lot of moving parts around the place. That's fine in itself, but it's the best if that's kept out of the playing areas and kept into specified detail rooms so people can notice them if they're looking at it but don't NEED to look at it. The helicopter in itself might be overly distracting but I'd have to go through the map to see that for myself at least.
- Don't focus on modelling only. It's probably unnecessary to say this because it's in the early stages, but while your models look generally good the detailing that's not modelling looks rather bland. Work on that first, then models - you've got enough of those for a while.
Best of luck!