The Zoom RFX-2200 and RFX-1100 are re-released versions of the RFX-2000 and RFX-1000. The newer versions have combination xlr and 1/4" jack inputs on the front (old only had 1/4" inputs). The new models also have built-in power supplies instead of external transformers ("wall-wart", "line lump") supplies.

Zoom also says the processing has been improved. Unclear if this is the DSP or physical outputs.

See: https://www.soundonsound.com/reviews/zoom-rfx2200-rfx1100