I agree, the diff between the stock and 10" is very little. I went for 12" Yaffe and could not be more happy with the set. I did it myself on older '14 Ultra Limited and it all went thru just fine except on one side i discovered i missed one wire and hell broke loose when i tried to pull the wires back up, etc.. when you have to worry about Heat Grips it adds an extra care (esp. when Yaffe design is not really curved like the Wild1 out there). Nevertheless, you can find very nice UTube video from a guy who did it on his SG - great video. If you need more info info you can PM me and do my best to help. My current CVO luckily already came with 14" and I almost cant tell the diff between this and the 12".
Hope this helps.