I'm looking for a relatively inexpensive looper with more capacity than my DL4, ideally one that does well with adding phrases "in time" (I know some of the boss pedals had some delay-offset from when you clicked the pedal until when it started recording), and with the ability to switch sections so that I can record an A part and B part and switch between them. The ability to delete the last phrase added is also important. I think both of these (RC20 and JamMan) will do this. Is that right? Anyone have a strong preference for either, and if so, why?