I bought a Makita, rotary with variable speed.....but knew I would be working on boat quite a bit and also plan to use it on vehicles. I hear Harbor Freight has a cheaper one and sure it will do fine. I would say it is important to have the variable speed tho cause you can "burn" the gelcoat if you go too fast. I started @ 600rpm to spread compound/polish and did first 2 passes at that speed and then sped it up to 1200-1500 max for another 2-3 passes going side/side and up/down over each 2x2-2x3 section. Time consuming and probably spent around 16hrs doing the wetsand, compound and polish, but I am a perfectionist and it was worth it once done.