The first part of this stage is a little weird. No one ever set up in the first red buildings that the cart went through, I think, so that part was basically a breeze. They mostly set up in the larger red building (near where RED exits when going to the first point), which generally was closer to BLU anyway.
Maybe they were just scared by the sentry props. Yes, I know why they are there, and yes, I know you're tired of people complaining about them - but I wasn't there when you apparenly explained this on some other gameday (or so I believe you said this Sunday), so I don't know why the hell you don't put them in a visgroup and disable it when you compile. The thing is, no one ever built a sentry in or by a sentry prop, I believe - the sentry positions your props suggest might be more frequently used if the props aren't there, as I can see why people would subconsciously avoid setting up in areas cluttered with non-solid props.
The second part was nice. I'm a sucker for great use of height, which you definitely had lots of here. Seems like your overall theme kind of disappeared at this point, but I thought it played quite well.