In my book a good sugar apple (A. squamosa) is absolutely worth growing, its just that most atemoyas are going to be better, and proper cherimoyas (A cherimola) will be better still. I might have some McPherson cherimoya fruit set down here in SWFL, keep your fingers crossed for me that they hold to maturity. ;-)
For custard apple (A. reticulata), I'm a fan of them because they bear in the spring when most sugar apples and atemoya aren't holding fruit here in Florida. If I could grow atemoya year round though, I probably wouldn't grow any custard apples. That said they're a good fruit in their own right that bears when many others don't, so I'll try and find the best custard apples I can to keep me eating annonas as close to year round as possible.
For my tastes even the lowly Gefner atemoya is still a great fruit for Florida, ranking above many other things we can grow here. Lisa is hands down a better fruit, as is Dream, but I'd still eat Gefner all day long.