Do you have a need for anything from the HR-20 now?
If your HR10 is doing what you want and you have the HD locals with OTA, then maybe there is nothing for you to really want right now.
The only reason I changed is I got a new tv and thought it would be nice if I could use HDMI between the receiver and the TV. My HR10 HDMI port was/is broken when I tried to do it, so I got the HR20 as a replacement. Glad I did because personally I am enjoying it, and like it more than the HR10. The HR10 is still pulling duty in a bedroom but the HR20 is in the living room on the big screen.
If you are concerned about getting hit with the issues that are plaguing some users, and don't see any clear benefit other than it might be fun, well that is something for you to decide.
You could really go either way.