Just played b5. I also havn't managed to play this since b2.
One problem i found was a lot of bumping into things. You need to add a lot more 'smoothing' clips to objects that stick out here and there.
I got stuck in there. Also, raise that wall, spies i noticed have free roam almost anywhere on this map untill the last point. Restricting their movement would not be a bad thing. It would also give defenders a reason to go over there as at the moment it's easily assaultable ground. The only other high ground has a blu spawn exit on it.
Increase the ceiling height here; it attracts
a lot of spam and basically anyone who goes down here gets stuck to the ceiling by the force of explosions (including ubers). Which only emphasised the issue of bumping into the truss's on the ceiling. If you don't increase the ceiling height atleast make the truss's func_illusionary to give a little more space and stop people from getting stuck and unable to proceed down this corridor.
This was a really annoying prop. I dunno how you've clipped this but i assume it looks something like the green bit? Either increase to add the blue bit in your clip or remove it all together. I saw a lot of players getting stuck against it (including myself) whilst trying to retreat.
I kept catching this also, probably need to increase your clip around it.