Despite releasing the M9 gimbals only a few months ago, FrSky have decided to release an upgraded Hall Effect gimbal called the M9-R.
Compared to the regular M9 gimbals, they seem to be almost identical when it comes to almost everything. The only differences we can see is the red colour scheme and decreased throttle travel range. This should result in less resolution, but you can quickly change from 0 to 100 throttle very quickly. This could be preferable if you are a 3D Heli pilot.
We doubt the small differences makes it worth the upgrade for those who already have the M9 gimbals, however if you are thinking of upgrading your gimbals from the stock ones, it would make sense to go for these instead of the M9 ones.
Read about the gimbals on the FrSky site here