Having spoken to the man who designed the G7, it seems that there were problems with the originals (the plastic trigger snapped off) which led to a change in design. His attitude seemed to be that if this happened he would simply give you another one.

The "Performance" capo was produced as answer to the Keyser for people who insisted on a spring loaded jobby. I got the impression that the he thought that the original G7 was better.

I've used the original G7 on several guitars and the banjo one on a similar number of mandolins and had no problems with either.
Ray