I have it but as it's only a few weeks old, I haven't used it much. I find the instrument very well done with interesting samples of the various synths. There is also fairly extensive programability on top of the sampling. There were a few glitches right around release, but UVI has released 4 small updates and I know of no issues at this point.
I had SAI and this is a HUGE upgrade - I'm happy with the purchase.