Hello chad can I ask you. I want to buy a rupes 15 or 21 I have a flex 3401 and gg6 da along with makita rotary but i want to get a rupes which one do you like. I have posted on auto geek and no one wants to really gave me a good answer but I do trust your judgement. I want to try and get that mirror finish.. Just a hobby for me but I do like it a lot and do my families and friends cars thanks and merry christmas. Reggie