So, you have have serious problems with optimization and fps. I wanted to find out how fps can be so low and shamelessly decompiled your map. What I found wasn't very nice.
Simplest and most common problem first: sealing the map. Here is how you have done the middle area of the map
There is a lot of useless space inside the map and you see the starting are from the right side. I won't edit your map to show what you should do but here's simplification:
Here is the basic shape of your map
Here is how you have sealed it (removed ceiling and the one brush that would block the whole view)
That's far from optimal and it makes whole map load at once. Here is how you should make it
Hugging the borders of the map with sealing will really improve the fps in your map. Also, there is no reason to make random brushes like these
Keep the brushwork as clean as you can. And actually that leads to the next, a lot more serious problem.
You have built everything in 1hu grid. Everything. Close to all brushes are weirdly sized like this
Usually maps are built in 16hu grid that makes all brushes to be multiples of 16, for example 256x128, 320x192 and 64x48. Using 1hu makes shit ton of
visleaves when compiling ( I assume your vvis takes ages too).
Here is the example map that is built with 32hu grid. As you can see, there isn't many visleaves and they are pretty clean
If I now build the same thing without being careful about snapping brushes to sensible sized grid I get this mess
It doesn't look too bad yet but when you add more horizontal brushes and more complex structures the effect will be huge, like butterfly effect.
Also your map is so big and complex that I imagine it being painful to even make brushes line together with 1hu grid. Bigger grid will make that a lot easier too.
Here is how you can enable snap to grid and where you can see the current gridsize
(that's bottom right corner)
When you build smaller details, like stairs, you can use 8hu and 4hu, maybe even less but always use as big grid as you can practically.
This isn't nice thing to say but I'm not too nice person anyway so it doesn't hurt: You have to delete every single brush and remake the whole map. There is no way around it. (Don't actually delete the map file, make a new one and copy the same idea by hand to the new vmf.)
Personally I like the layout and it has real potential but the mapping behind it isn't acceptable and has to be fixed. If you have trouble understanding optimization later on,
here is a good read to begin with. If you have more problems, TF2M is always willing to help.
For other readers and more experienced mappers, let me know if there is something missing or wrong in this post.
After all the serious talk, here's a final relief from a train I'm currently travelling in
http://i.imgur.com/oI94Sff.jpg
