I still think 1 point per round is the way to go for plr, but here it really gives you an advantage in round 3.
Pretty good ideas, I think (almost) everyone loved the cart that crushes you before round 1 and the cart falling to its doom in round 3. I did, at least.
Concerning the map layout itself, I have no comments to make, it seemed fine, interesting, and balanced for every class. We saw very little use of medics but I think the lateness of the map in the gameday caused everyone to go a little "w+1" inside.
One thing you may want to do is add some props or small heights here and there to allow heavies to jump on the cart. Though there are places where you actually can fall on it, I think it's nice to have a heavy on the cart during setup.
Some of 'setup gates' (referring to the props used, they are actually respawn room doors, I think) go through the roof ad pop up on the other side.