My immediate response was going to be NO WAY!
But that's only because of latency issues and needing to resync all the time, well and the infamous crackle, anywho, before I understood how to set it up to utilize the 16 channels playing simultaneously, I would just run 1/8" outs to my interface. That was the ticket for getting the massive sculpting power on the fly without having to deal with VC (or any software at all for that matter).
I've brought it to jam with friends (mostly to show off ) and come to think of it I really like the freedom of not having all the perimeters readily accessible because then its more about playing.
So to sum it up: Yes I'd use it live but only if I was not using USB and I had all my patches cued to the beginning of the library and had practiced each knowing what I was going to do with it. But I don't think thats why you own a TI. I think its really meant for studio use.
I think I remember seeing an older one briefly in the setup for a massive show in a Radiohead documentary.