Upload & Sell: Off
I have a cheap 'Nipon' branded ring. Just a shameless copy of the Kipon. It works OK with my Sonnar-G 90.
One thing I found is that when the adapter+lens is out of the camera, turning the focusing ring is a PITA, very stiff or even stuck; but once is mounted on the NEX it works reasonably well.
Even so, I'm thinking of replacing my Sonnar-G 90 with a C/Y Sonnar 85/2.8. The focus ring isn't the only ergonomic issue with G lenses. You haven't a focus scale on the lens; pre focus isn't possible. Also, the G mount isn't compatible with other Mirrorless systems, ( as the Ricoh GXR M mount A12).