Most will end up recommending the Edgepro or Sharpmaker, with the Edgepro being better suited for reprofiling and Sharpmaker for touchups.
I don't have either, so I can't really comment on those, but I have a DMT aligner which works on the same idea as the Lansky. I find that this system works well for sharpening medium sized knives, but doesn't work well with smaller pen blades. It can do larger knives, but you have to reclamp the sharpener at different sections to cover the entire knife. As a consequence of geometry, clamped systems will begin to create a more acute grind toward the tip, assuming you've clamped the knife near the handle.
I've considered the Edgepro myself, but at the moment I'm trying to learn the basics of convex sharpening. It just seems to be the most practical solution. Search for the "mousepad method" and you'll see what I mean.