Well, the Rev Jr is pretty damn close to the Rev+, just not moving that much air due to the scaled-down power section. If that's any indication to how the 'stein Jr sounds then you can expect pretty much this. But beware: Some people have a rather hard time working the sweep knob on these amps. Finding the sweet spots according to your playing and style is absolutely crucial to get a great tone out of these.
The Rev Jr Pro has been the single best amp investment I've ever made.