how does this work?
All I see is that it uses springs to maintain string tension. Surely you'd still have to retune to compensate for changes in temperature, string aging etc. Also the spring would be subject to temperature changes and it would appear screw up your ability to do bends.
I'll stick with manually tuning, if I really needed a self tuning system I'd by a robot guitar so that I wouldn't have to butcher a perfectly good Les Paul to put that monstrosity on it.