The Gamut guide was one of the easiest to fit chainguides we've used. It also has some neat spacers that fit behind the top rub guide to fine-tune the fit – the lower roller is on a threaded system so it can be perfectly aligned. Gamut have changed the compound of the lower roller too, so the guide runs much more quietly, with loads less clatter than the older P30s.
The P30 does still create a little more noise than a few other chainguides we've tried, especially when in the first couple of gears because of the way the chain clatters on the wear plate. There are also no chainring bolts included which is a bit of a pain.