KME clamp is self adjusting and also has rubber inserts that also compensate for any play there might be left. I upgraded from a DMT Aligner, which is pretty similar to the Lansky system, but it had a second screw that allowed the clamp to grip at an angle so flat ground knives were not an issue for it.
KME was a night and day difference, just put the blade in there, wiggle it around to make sure the clamp grips it, tighten and get to work. If you do go that route, get the version with the diamond plates, and get the stand, it makes things much easier. Also make sure you limit the range of motion of the stones, so you don't slip off the edge and damage it. I use orings. And this advice goes for any fixed angle sharpening system, don't let the tip go past the middle of the stone (width wise), otherwise it becomes easy to roll the stone over rounding off the tip. Rounding off the tip can eventually lead to a dull tip.