I use one fairly often for bending EMT up to 1 1/2".
Bends need to be made in stages, and be exceptionally gentle. I suspect a 15 degree bend is about the best you can do. As noted already, the shoes are not really sized for EMT.
As you might guess, the main use is for bending offsets.
I have been told that you can do 2" ... I have not had any luck on the two bends I've tried .... as well as more aggressive bends if you fill the pipe with sand.