No, most of my time with Vega has not been in my own system. I had one come through briefly but only had time to use it with the matching Taurus amp. I see no reason why it wouldn't make a great combo though - I go the other direction and use Questyle's CAS192 with the Taurus all the time, with excellent results.
Makes sense, the Vega would probably work fine with the CMA800. The CAS192 is likely voiced similar to the the Vega (not too tipped up) or it wouldn't work so well with the sometimes aggressive HD800s.