I picked one up myself a few months ago. Got it used with the Control 2, a MosValve MV-962 and a 4U Gator rack case shipped for less than a new GSP. Right now I am using just the GSP with my recently acquired Fender Prosonic head and its fantastic. I can flip seamlessly between models and the Prosonic preamp, and I can add tremolo and a noise gate to my physical amp, something the 11R could never do.

The GSP is the clear winner for integrating into a live tube amp rig, but the 11R models are a clear step up in quality