If you want easy slide, install teflon strips.
Most people I know they tried rollers, pvc pipe, teflon and all came back to normal bunks after they dropped the ski on the ramp.
I prefer normal bunks, ski sits more stable when trailering around too. I have to launch/ recover in very shallow water most of the times and launching can be a bit difficult sometimes but recovery is always with the winch, no issue.