Listen to the difference live....
Solid state amps can acheive great distorted tones but I've noticed when you check out a band live, the solid state amps get lost in the mix. For example; I love Prong (I'm listening to them right now on iTunes) and I've always thought Tommy Victor has had a great tone. He plays solid state Marshalls. It sounds great on a recording but live I have always thought his tone gets lost in the mix....especially when he is playing with another guitar player. I love Prong's sound and the tone Tommy gets, it's just not what I'm after.
I think amps like the 5150/6505, Randalls, and the Krankenstein that try to sound more "tight" like a solid state amp are missing the point. The whole point of a tube amp, in my opinion, is the thick, liquid tone that cuts through the mix like a knife. I still think you can get tight, punchy distorted sounds out of tube amps without compromising attack, tone, crunch, or anything else.