You all have valid points. Definitely all things I've been taking into consideration when building my cage. (As a side note, I also made sure my doors were large enough that I could fit head and shoulders through them. Best. Idea. Ever.)
So, let's have a hypothetical discussion then. Say for instance, that you're cage has levels or oops hammocks spaced appropriately so the distance of falling isn't ever more then a few inches, and an integrated carrier or smaller cage in which, should you need to get the chins out in a hurry, you can herd them into. Assuming these things, how big, is to big? Is there a to big? And realistically, how much space does one or two chin require? How much is the ultimate amount? And, if you had it your way, what would be YOUR dream cage? Cleaning issues non withstanding, of course.