I,ve got one, haven't used it live. It works really well though, no tone loss that I can hear. What bugs me is that the manual reccomends not to use either of the amps FX loops. I've used it at home for A/Bing amps and tweaking tones.
I've got one, as well. was using it with a MKV and a roadster with a gcx to switch fx loops. 7channels of maniacal bliss, worked perfectly. pull the trigger!