I've narrowed it down but...

let us know how everything turned out...I shopping for an av receiver too.
Not sure weather to get newest 2.2 hcd 4 k or not

I ordered the Yammie rxa740 and bds677 on Wed morning and received it on Fri morning. Fast shipping from A4L.

I upgraded software on both units to the latest available from their website using a usb thumb drive.

I've begun setting it up using their mic for a 3.0 system with the L/R speakers bi-amped (rear speakers and sub will coming later) The sound is quite boomy. I looks like the shown frequency response has big bass peak and mid-bass peak. Wonder if I should manually adjust the response so I'll have the play with it to tweak the sound, but I work today and tomorrow so it will be slow going.

Tough my center speaker are 6 ohms and L/R are 4 ohm, I tried the 6 ohm impedance setting but it looses dynamics, so switched it back to 8 ohms.

Over all sound is clearer and more dynamic than my 23 yr old Denon stereo receiver. I'm liking it.

Turned off various dynamic sound features and re-calibrated the system. It sounds clear, balanced and wonderful now. Sacds and hdcds sound stunning.

The system is so revealing it is easy to hear the improvement in sound stepping up from CDs to HDCDs to SACDs. Sound is very involving which I thought was not possible w/ an AVR and Bluray/SACD player. I think I'm a convert to home theater. BTW, movies are staggeringly convincing too.