Sorry, I've been "away"...
Yes, I did try the Tube MP (had 2 - an old one that I bought used and a new one), also had a couple of the Levelars the ART tube compressors). Didn't find them to be anything special, there was some subtle distortion (bad kind), there were problems with the LED, it doesn't like just any tubes. And most importantly: it's very space-un-friendly, you'll have a spider-web of wires if you use more than one. I ended up building a rack and the Presonus fit lovely in a rack. They are 2 preamps for less then 50% more than the Tube MP, they have the inputs on the front panel, better metering, YOU choose wheter to amplify cleanly or to drive it through the tube and color it. They may not be a Joe Meek or whatever, but they sure do beat the Tube MP. I have 2 of the Blue Tube-s in my rack and I record everything through them now.