I've never noticed any latency - I think it depends on how you set the patch up.
The other thing worth mentioning with the Minitaur is that for patch selection and programming your gonna need some kind of software support, ie a laptop or tablet. You can select patches on the front panel but I'd say it's easier with a visual representation of the patch banks.
And yes there's a vid of Billy Sheehan using them live and also one of Doug Wimbish in one of those rig rundown vids. If they're good enough for those guys...
On a general note, I'm surprised that one of the synth manufacturers didn't pick up the Taurus baton over the years and make a stand alone Moog clone with the four sounds from the original that everybody wanted.