In late 2019, I took an opportunity to upgrade the SkyWatcher EQ8 equatorial mount in my dome (see full disclosure below). In my case, I chose the EQ8-Rh option with high-resolution optical encoders on the R.A. axis, rather than the new 'vanilla' EQ8-R.
Despite my astrophotography experience, I'm not an expert in the construction, mechanics or operation of equatorial mounts. But let me start with my take on the changes in the the base version EQ8-R compared to the first generation of this mount before discussing the remarkable encoders in the Rh version.