These Mesa Boogie shills that are bagging on the prosonic are clueless. The prosonic is a badass little amp. . .and mine is sitting between a 64 twin and a 65 super reverb, so I know fender tone. The prosonic is like a modern super reverb with an extra gain stage rather than vibrato. The clean channel has great tube break up at high volume- like a blackface fender except it breaks up more (with hot pickups, you can get it feeding back when you dime the clean channel) and the quality of the breakup is better. The gain channel is cool, but it sounds best (like most high gain amps) running a distortion pedal through the clean channel.
Anyone who says the prosonic is a bad amp, or that it doesn't have great tone, is a complete idiot and their opinion should be disregarded.