In terms of accuracy, durability and value, I think the Kmate is outstanding. I've strung over 100 frames in the last 2.5 years.
Yes, there are better machines w fixed clamps, 6 pt mounting... etc. But for just a personal machine, or to help out a few friends, it's awesome.
Volkl C10 Pro w Pro's Pro Blackout 47-55lb. Still rocking my Klippermate.