Based on giving them a very good look, side by side, when I worked for Klingspor, I'd say; #1 Fisch, #2 Jet then #3 Delta. I haven't spent any serious time looking at the Rikon. From a distance it looks a lot like the Fisch. I have the Jet and it has been ok. The plastic variable speed control box is not very well made and the hinges have broken loose on mine. Nothing that can't be worked around. BTW, I do use the variable speed but only in the mid-speed range. I've never switched the belt even one time.
Rob