Since starting to use Shubb capos I just can't switch to anything else, they work really well. Being able to use a screw instead of relying on a spring loaded mechanism ensures that it will work equally well for all string gauges, neck lengths, fret height and actions, as the string tension can never be high enough to counteract the stable locking mechanism used in these capos.
I also recommend the aluminum versions of these capos, but nothing beats steel for pure feel. It's simply a solid performer.