That's in in a nutshell, although I confirmed for myself last night that you can process "depleted" nuclear fuel in a basic centrifuge.Thermal centrifuge can be used to process nuclear fuel, if im remembering correctly it basically replaces the IC2 one - @Pyure will be able to tell you if im correct or not, i'm still faffing around with LV turbines here ...
The difference comes down to: what it can process, how long it takes, and how much it costs to do it. Sadly, I don't think the NEI shows what it can process or how long it takes, so its mostly trial and error.