There aren't really any major differences but the Sharpmaker comes with a lot of extras. The V shape sharpeners are pretty simple in their techniques and don't exactly allow for much variation. The angles are set, though, so there might be variation there--the Sharpmaker has two angle settings (30 & 40 degree) while the others as far as I know only have one. Another difference would be the triangular shape of the rods on the Sharpmaker allow for sharpening serrated edges and grooves for sharpening fish hooks and such. Sharpmaker also has a couple of extras in that there is a 12(?) degree angle on the side for sharpening scissors, etc., and if you flip the base over you have slots for using the rods flat. The Sharpmaker also has the hand guards for protecting your hands during sharpening. Sharpmaker has optional rods--ultrafine and diamond, and it comes with a really good instructional video on how to sharpen pretty much everything. And the last thing I can think of--and I'm not really sure about this because I haven't seen all that many of the others, but I think that the Sharpmaker has the longest rods out of all the v-type sharpeners. I think I covered everything...