I've had both types of cages, and I can see pros and cons to both. I used to have dometops, but I think I like playtops better now.
I do like the added play area with a tray on top so that poop doesn't fall into toys and bowls inside a dometop. I don't find it's any harder to clean. Raven and Griffin's get dusty, but not 'dirty'. Just a wipe down is fine. It was hard to find a cage as large as Raven's without being ridiculously tall. I finally found one model which was the perfect size AND height at King's.
Drawback of platops is there is less "head room" with the flat roof. Makes it seem smaller and like a closed in feeling much more so than a dometop of the same width and depth. Also if you use the top tray, it makes it darker in there too. Much darker than a dometop. Overall though... I still like the playtop a little more, and I think I'll stick with that.