The tube amps themselves are more similar than you might think, with most of the old tube heads being either the Sceptre under various names or the 200S under various names. The larger heads, such as the 2000S, have the same preamp sections and larger power sections. There are a few variations, but not many, and tonally they're almost identical. The Model T is it's own beast, though. Actually, more than one. The first generation (1G) amp is one thing, and the 2G something else again. The late 90s Fender Model T is a completely different amp again. I know very little about the Enforcer, but I suspect that it's unique, too.
Along the same lines, the solid state amps fall into just a few general classes. The silver and black Concert series amps are all similar, the black Concert amps are all similar, and the Coliseum amps are all similar.
In my opinion, all Sunn amps share a family resemblance in that they all tend to be very clean and powerful. They take pedals well, but are not famous for their own distortion. Although, I did read an interview with a famous guitarist - it was a long time ago, and I don't remember where I read it nor who the guitarist was - who said that the best distortion in the world was a Sunn Concert Lead, cranked. He likely had stacks of Marshalls on stage for show, but definitely had a Concert Lead backstage, miked into the PA.
