I have. The layered ones seem to change voices too quickly, so I'll need to edit the velocity switching, but the actual vocal samples are much improved.
I'm about to leave for work (all guitar , and banjo tonight) but tomorrow I'll hook up a sustain pedal, and a mic and see how this puppy performs.
I'm not expecting miracles from the VH2, but if the preamp sounds good enough for my guitar, then I'll use a TC unit for my mic, and feed it into the aux in. I've got choices, and I intend to explore each one.