(With Yamaha 4C, Vandoren 2.5s)
Due to the soft material it fits much better than a metal ligature. I had a Rico RAS1 shortly before this, and the GF is so much better that I never touch the RAS1 now. The single screw is much faster to adjust, it eliminates the reed squirming when you would tighten two screws. The lig grips the mouthpiece much more, so fitting works a little different but it definitely saves time. The crosshair alignment pattern is somewhat useful, but my biggest issue is always seeing how centered the reed is on the mouthpiece itself.
Playing, the reed feels very supported. I can have the lig quite far back and it has really helped with altissimo (up to C) and lip out embouchure. I haven't noticed any darkening of the tone from the lig alone - that certain brands claim for soft ligatures. The only issue is it's easy (coming from metal ligs) to overtighten the lig, and I feel like I stretched mine a bit playing this way for a couple of weeks. It still works well but I'm conscious that I could wear it out if I'm careless.
The cap fits perfectly, and as others have said the beak looks like a duck when the lig is fitted. The cap comes with 3 sticky foam pads but I didn't need them. The flat end of the cap lets you stand it on end. Instructions in German only, and the sizing system is vague.
It seems nearly perfect, been using it for a few months now, the only other drawback is the brass rods can vibrate subtly on the mouthpiece. I didn't notice this when playing, but over time it slightly rubbed off the logo of my Yamaha 4C where it touched.
