Of all the Lee single stages I would recommend, it's the APP. You don't have to use the case feed system if you don't want to, but if this press is only for one caliber there'd be no reason no to as you would size and flare cases much faster.
You wouldn't be able to charge cases on the APP tho, so if you were looking to do that avoid the APP.
I do own the C frame you're asking about, I bought it specifically to use the Lee Auto Disk as none of my other presses allowed for that. I have used it occasionally and have no complaints. The Challenger is a fine press, but for just handgun use only I think it's overkill and a waste, the APP is perfect for use with handgun calibers.