The RAS 115 grinds every bit as well as my 4-1/2" Makita but when used with the dust extractor (CT22 for me) it collects better than 85% of the dust. Grinding for fiberglass repair (like tabbing or hole repair) need not fill the boat with dust any more. I was really surprised at how effective the dust collection is. It's not cheap but neither is a lung transplant. After hours of use clean up is basically washing your hands. The stuff it doesn't collect tends to be larger chips not the fine dust. I would still use a proper respirator though.