@Al Krow,
The volume knob is notched and each click provides an increase in loudness. In my opinion it's smooth. My Quilter is very similar in that regard and my Ashdown seems to give you more earlier in the stage especially when the compressor is engaged.
The Mosfet is definitely the more modern sounding of the two heads. The Tube has more of a low-mid presence with controls set flat on each in my opinion. I don't have much experience with full blown tube amps. The T does offer more warmth than the M but there wasn't a night & day difference to my ears with the gear that I had during the period when both were under my roof. The cabs that I had then all were a little more vintage sounding. They were a pair of old Genz Benz 112s which I still own and two pairs of Ashdown cabs without tweeters (Mi 10 & ABM Mini 408 Neo). The T isn't wild & woolly and the M isn't sterile. They're each just nice clean sounding amps but again, I do feel that T is warmer.
My experience with compressors is also not very extensive. I've owned a couple of quality pedals that didn't get used much. I'm sure that there are better compressors but with the limited amount of usage that I have given the unit on the Veyron, I can't say that I've encountered anything that turned me off. Here's a video of the Veyron M being played by the same guy in the previous video that I posted. He's got the Ultra High & Ultra Low engaged which sort of sccops the sound....