Get the RME...you know you want to. Rock solid USB drivers (RME was imo the first to really nail this down, it's not easy), great converters, and truly legendary support for products sold long ago. I know people using RME gear they bought 10-12 years ago, and running them on new PCs/OS. Can't say that for many others. Has RME ever actually stopped supporting a product?
You getting the UFX? What a piece of gear that is.
And TotalMix has quite a learning curve, but it is really phenomenal, deeeep, and can do about anything you'd need from it.
And you're right. I don't care that there is no USB interface, and I don't have a need or use for it, but it's so silly to act like the KPA is so special or different in some way, that an interface wouldn't make sense. Bullshit, it would simply be product parity, as you say. Modeler/Profiler is so irrelevant to this argument.
Yeah, UFX it is.