Since keeping the servers full is the primary concern, why not ask the public players? Run a poll on the website and request submissions via the server? There's a massive list of consistent regulars who would more than likely like to have a say. That way you can see what your traffic wants to see and use that to make a decision that makes everyone happy.
Personally I think the original maps were good. My thoughts on armored kill content is the same as almost everyone else in XI I've talked to (maps are huge and a pain in the ass to get around), and close quarters is okay (but I like playing BF3, not CoD). The best thing out of CQ was Gun master; that is a mode I enjoy every now and then (along the same lines as scavenger).
B2K city maps are fun but they sure do feel similar to Aftermath...just more polished and uh...grungy, if it's possible to be both at the same time.