Blues Jr. is 15 watts. Hot Rod Deluxe is 40 watts. Other than that, I don't know what the differences are. I'm leaning towards getting myself a Pro Junior, but lately I've been advised to get an amp with a master volume control, so I'm considering the Blues Junior as well. Pro Juniors are supposed to haver better tone, though, so I guess I'll have to do a comparison test at a shop that has both amps. If you want to know all about Fender stuff, this isn't the place to be. But this is: http://www.fenderforum.com