I didn't get to play in Operation Payback, but when I saw this map in a video showcasing all the operation maps I immediately went to download it. While it's not a very conventional map I'm surprised that Valve didn't put it into the Demolition map pool. If Oskmos has any way to get in contact with Valve I'd love for him to suggest this.

It has one bombsite, is very close-quarter and rounds are usually fairly short. That's literally every demolition map ever, and this would be a great addition to it.
(Seriously though, people who like demolition are stuck with a very narrow selection, especially when you consider the fact that people always pick the same 3 maps).