I got a chance to compare the Veyron Tube version with the MiniMega. I tried it in a store with several of our cabs. The Peavey has lots of power and lots of features, I was particularly interested in KOSMOS and spent a big chunk of my time experimenting with those two adjustments with a Tank 1012. Then I a/b'd the Peavey and Bugera several times.
My conclusion: the Peavey has more features which is cool for folks who need features. I have basses that already sound great so I don't need the tweakability. The KOSMOS is interesting but I prefered the lows I could dial in at my bass vs. kicking in the circuitry. I was really looking forward to some magic with the KOSMOS and the little Tank 1012. It did make it sound deeper but at the expense of tightness and articulation. Of course a different bass and/or cab could yield different results... I was using my Surine Affinity 5 with Bartolini pickups and Aguilar OBP-3 preamp. The bass control on the OBP-3 is the the poster child for a little goes a long way.
I've been gigging a Mosfet Veyron for over six months so the Tube version was very familiar. I set all of the controls either flat or off, played with the gains and got the same clear, punchy, deep, aggressive sound I'm used to. I didn't get the same with the Peavey set flat and while I probably could dial in a similar tone with the controls on the Peavey... I'd rather not have to. So, while the Peavey is very nice and I don't think it would be a bad move by any means, I prefer the Bugera. If there were no Veyrons or Kustom KXB500's or Genz Benz Shuttle 9.0's (the three amps I gig with regularly) the Peavey would definitely be on my radar.
Chocolate vs. vanilla. They're both ice cream so it's all good.