Well, after a few tries, I can now get on top of the crates... but I think you should add maybe 2-4 more paths that go to different sections of the base, without the crates. Have the paths slanted up too, so you can gain speed. That's what we need in a speedball map.
This would help a few things:
1. base would be more easier to get to
2. newbies would have an option if they can't manage the crates. (like me
)
3. base would be harder to defend because you'd have people coming from more directions
4. More paths are always nice
Something like in my drawing: (but please do it better than I did, this is an opportunity to include some curved walls!
)