I can't give you a comparison, but I use a belt sander 1" X 42" with a 120 grit blue green cloth backed paper ... Cost $2.18 each, after 5 months it is still perfect. I have the table tilted to about a 45 degree angle, so it will sharpen any size. The angle is totally flat, no heat build up, almost no wear on the gouge ( I have only done 65 bowls) you can not tell that the gouge is any shorter at all. The 120 grit leaves a mirror finish on the bevel, it sure seems sharp. I think this is how a lot of knife sharpeners do it. Total time from turning on to turning off the machine is possibly less than 15 seconds. Speed was one of my goals so was not spending money. I accomplished both. Practice was fairly quick also.

Good luck,

On your travels between SC and VA feel free to stop in and have a look and use my set-up to sharpen yours, I live about in the middle.

Dave