What would the USB add to it?
For me, a 4x4 interface built into the mixer I was using anyhow would be super handy. The alternative is to do what I do now and use another interface (RME Babyface) and have to repatch things. I may bust out my old Behringer Totally first world problems here...
General purpose recording with any guitar processor is not for me. They're all fine for their intended purposes but they're all a hassle (to me) for recording anything other than a guitar or bass.