My zipper will out clean my rx 20 and both my pro chem wands ..with the same water flow
Advantage of the zipper over rotary:
No electric cord
Less weight
No swirleys or raking
I have found with enough water flow and vacuum I don't need agitation
Gotta have at least 10-12 flow and kero or propane heat full throttle no triggering
Pressure washer guys clean concrete with high flow and high heat. No agitation