I've strung over 100 frames with a Kmate... VERY durable machine and I'm extremely pleased with it.
I have not had an issue with the 2 pt mounting system. When I string mains, I'm no more than three mains ahead on any side.
As others have mentioned about stringing poly, the "trick" to the Kmate is knowing how much slack to have from the racquet to the jaw based on the elasticity of the string.
Other advantages, IMO, are:
1. Clamps... METAL and very durable, like the machine.
2. Starting pin... extremely useful in avoiding a double pull in the mains.
3. Support... They will replace broken equipment, for free. Friend of mine broke a clamp and the replacement was in his hands in 48 hours.
4. Storage.. I store the machine and all my string in a 28 inch Stanley Fatmax tool box. Also has nice tray to organize my clamps, tools and mounting hardware.
My average stringing time is about 30 minutes. Hope this helps. Great value in my opinion.
Volkl C10 Pro w Pro's Pro Blackout 47-55lb. Still rocking my Klippermate.