I'm with ernestrome, the edgepro seems like the best midpriced aid. I have had the best results with a 1"x30" beltsander with many grits of sandpaper. I began with pieces of 1/8" flat stock until I could run consistant bevels along 10" long pieces. Then I used 8" round pieces. The most difficult thing with power sharpening is consistency of an edge. I have tried the slow moving round wetstones and have always had problems with them grabbing the blade, creating more work than when I started. With a belt, you just make sure your draw along the belt is continuous from heel to tip.
The paper wheels work very well, but take tremendous concentration and a lot of practice for the results most want.
No matter what you use, safety can not be overstressed! Even sharpening by hand can bring many stiches, power tools can lead to body parts in ice chests with doctors saying, "I'll do the best I can, but I can't promise anything."