It will be my only one and I don't know why...... I just want the damn thing. I was reading a lot today..... A dangerous past time when it's slow at work..... Buff daddy's site says that you can use the bigger backing plate that's on the 21 on the 15 with no issue and vice versa. My biggest issue is weather to hire a pro to get it perfect or try to do it myself. I'm inclined to spend the money on quality stuff one time rather than be disappointed and buy the wrong stuff.
Same with the polish and pads ...... Where to start ......