As lame as this reply is, I just really really like how they sound. They act more like the real amps I'm used to using. I don't do a lot of heavy rock stuff. So for amps like a 59 bassman, a Dr Z, Matchless, or Vox AC15, the sweet spot is usually somewhere right around where the amp breaks up but before it starts self-compressing. The way the guitar breathes in that sweet spot on the Scuffham just seems more accurate than the others to me. I also hear much more of a difference between the models than I do in GTR rig, amp farm, or Waves. The UAD probably comes in second place, but they're sooooo expensive compared to the Scuffham.
About the high gain, the Soldano is the only amp in the bunch that was really modeled after circuit that was designed for high gain. I think it does it well. But as you can imagine, in real life, you wouldn't want to track a whole CD using a pair of Soldanos. I have a several Mesas, a Diamond, a Peavey 6505+ and a Carvin V3...I think the Scuffham Soldano is at its best when you blend it in with those.