Summary: I have had this unit for 5 years. Let me start off by summarizing. You can do a lot better for the cost of this receiver. It has every feature you might want, however it seriously overheats, so much so that it freezes up the video card and won't recognize hdmi inputs till it cools down. You can't stack it and you will need to buy fans to surround it. If you are ok with this you will like this receiver. Don't expect onkyo to help though.
Summary: Kumar is wrong, the Yamaha RX-V663 does not have a HD Radio built in tuner, for HD radio except for satellite radio, so that is one of the reasons this model is higher, the Onkyoa 876 is less but does have the HD The NR906 is particularly high, but that is because it also has a port for your internet so you can set stations that stream over the internet.