I agree with you Camille, Play Tops are a pain. Quito's Qage

has a top grate that is attached, so that's a plus. I don't like the looks of Ollie's top grate at all, you can see where a bird could get their head stuck very easily! Can't believe they'd design it like that. I have the top tray stored here in the computer room, since as you said, it blocks too much light. She is on the top sometimes while I'm cleaning but since she's pretty small, any poop falling through isn't too much of an issue. I can see where it would be with Ollie!
Tausi's cage is one of those Victorian tops that opens, but I leave it down and latched at all times. It's fairly heavy and doesn't open real easy and again, Tausi's not that big.
Chico's cage is a dome top, and is bolted together at the top. Definitely the most secure, and I think the best design. There's plenty of area there to hang toys and Boings from. He climbs around the top upside down just fine. Only thing is its quite tall, and with a territorial bird (like a grouchy and hormonal DYH

) if he were to climb up on top outside it could be quite an adventure to get him back down again. You'd need a step ladder to reach the center of the top. I'd probably opt to just wait for him to climb back in on his own.
Stainless is definitely the way to go if you can afford it. Probably cheaper in the long run anyway, I can see where these powder-coated ones aren't going to last too many years.