Fret wear due to which capo is a non-issue, IMHO. The bigger concern really is pressure on the strings to pull notes sharp, and how "fast" you want access to it.
The shubb is nice for the obvious reason that you can set the tension. But requires two hands to use or move.
The Kyser is fast since its trigger mechanism allows fast, one-handed use and movement. But has a gorilla spring tension that is fixed.
G7th is superb in its intuitive, seamless design and implementation. But two handed use is typical, though one-handed is possible with pratice. BTW, I use a G7th 12string version for my 12-er ...best 12-st capo out there, IMHO.
So for regular use on a 6-er, I like the Planet Waves Dual-action capo. It is a trigger mechanism for speed and one-handed use, but also a thumbwheel like the shubb so you can use the least amount of tension necessasry. The best all-around capo by far, IMHO. That it costs nearly nuttin is gravy!
Edward