My guitar teacher owns and plays a 1x12 Blue Angel and i have a lesson i love the clean and dirty sounds he gets out of it. On Musicians Friend the other day i saw the Epiphone and after reading the specs, it looks more and more similar. Besides the obvious differences (speakers, inputs,etc.), how different do these two amps sound?

See if any stores near you carry the Epiphone. A Guitar Center might have one.

I would imagine the Mesa would be the better sounding of the two. But, the Epiphone has 2 speakers instead of 1. The Epi is also channel switching which might be more functional.

The main difference is that with the Mesa, you can switch between 2 different power tube types. EL-84 and 6V6. These are gonna give you Vox and early Tweed Fender tones. The Epi uses 6L6 tubes which are found more in Blackface Fender amps.

Anyway, you are familiar with the Mesa, go and try the Epi if you can find one and decide for yourself.

two VERY different animals...If the price is similar...to my mind the Mesa is hands down the winner...heres the specs from Mesa...
http://mesaboogie.com/Product_Info/Out_of%20_Production...ngel/blue_angel.html
The Epi is a fine amplifier but...it aint a Mesa...one is a nice, but standard low cost production amp, the other is a fairly unique ( especially for the time it was produced) boo-teek ( Mesa may well have been the first real boo-teek amp brand) amplifier, and more of a "profesional" grade amp ( better long term investment?)...but as always it comes down to sound...which sound best to you... but to me it's like comparing an Epiphone Les Paul and a PRS Custom 24...neither is an embarassment but...