Managed to spend a lot of hours on this yesterday - I've got 3 jumps and the spawnroom well under way. I''ve started to make the first jump look more attractive with more final textures and I'm building the caves portion of the jumps in 3dsmax (like this)
I could use shadow baking on these sections - I'll see how it progresses.
Here's what I've got after 3 days.
@xandaxs - bots are so I can test a lot of players spawning at the same time.