Ok. You do realize that according to those criteria, dm6 is an awful map, right?
In my opinion, a good CA map has large enough rooms to fight in, interconnected in various ways, always leaving different routes to attack or escape. And that's coming from a non+backer.
Spillway : Bad because one of the room has a single entry point, which results in camping. (if people use it that way)
Almost Lost : Good for 3v3. Becomes a bit cluster****ish on 4v4 but still playable.
Eye To Eye : Bad for normal CA gameplay but good on 2v2 when all you wanna do is fight without any other consideration (like thunderstruck), which is fun from time to time.
Black cathedral : It is sadly so large that you will most likely always see your enemies from a distance and have to rail the whole game unless you manage to get on their back while they fight a teammate. Great with 8v8 and more. Another issue with the size is when the last 2-more survivors have to meet and fight : you can get unlucky and wait for a while before an encounter.
Seams And Bolts : Despite being so small it manages to provide distinct places to meet, fight, take cover... Good 2v2 and 3v3 (with teammates that won't let you die alone and lose, although it's their fault; not the map's fault).
Overkill : Good except for the fact that top is way too advantageous. You rarely see teams gather and fight anywhere else and that gets boring.
Asylum : Terrible totally open rail***** map with a side of FPS issues for a lot of people.