Does anyone had upgraded from the new RCD 310/510s to RNS 510 Unit?
I have done an upgrade from RCD 310 which came with my Golf 6 to RNS 510 (sat nav). I liked the new unit and its features, but was bit disappointed with its audio quality and radio signal reception when comparing to RCD 310s.

I also had a chance to drive a VW Passat loan car for a week fitted with RCD 510 and that was having a better audio quality (even better than RCD 310).
My RNS 510 unit was fitted by VW dealer, so I don't think it is a fitting issue.
Could it be because the RCD 310/510s are new generation units?