Tough call, they call have +'s and -'s.
BOP gets called out for being a left ramp wonder, but the truth is, there are more shots on BOP than the others. It's not a machine for competition but it's great if you want to practice shots and get good at pinball. Lots of ramps, loops and things to try to hit.
The ruleset is pretty simplistic on all three, a bit deeper on JB.
Theme, BOP wins. It has a rotating head, how cool is that? Music is better, call outs are better. Though Pinbot has some cool music and sound files as well - i get nostalgic when i hear it.