When I had my 5.1 system with 5200s and a G91 I tried an HD621 vs analogue out of the Denon Bluray I was using at the time, can't remember the model, and the Denon was just as good, which was a huge surprise.
On music discs the HD621 has an edge, but not enough to get me to buy it.

So worth trying it if you have some phonos lying around to hook it up via analogue.

No Darling, I've had it months!