I have both the G7 "performance" model and the Keyser (which I bought first). I rarely use the Keyser - the spring is very strong and it it has one tension which can put strings out. The G7 is tightened to the strength that I want, it's neat and unobtrusive and it comes of very easily. I can also mov it with on hand, if need be. The Keyser gets in the way of my fretting hand - but it's handy as a spare in the music room... I'd heard about early G7s coming apart or locking, but mine's fine so far.