if you have a shalow draft like mine, ( yes neal i have ysed the boat befor i started woork on it ) skids are fine.
if you have a deep keal or a v keal then rollers are better.
if the slipway you use is a very flat shalow gradeant then ?
i have used the slipways at swanick, calshot , pool , with my carpet side skids with no problem.