Ok, I've been playing with this receiver quite a bit and it's very different from the Denon as would be expected.
MUCH SIMPLER! But at the cost of some features.
One thing I found is that every input can't have it's own speaker levels like the Denon AVR-2312ci. It can temporarily but only for the fronts, center, and subwoofer. No rear channel level. Since it's temporary it must be just to compare. However the Onkyo can take the stereo input and play it through any pair of speakers setup. The Denon couldn't. This is a great feature for listening plus it helps to see how close timber is on all the speakers.
I noticed one thing I'm not fond of it but there's trade offs. The network feature for Pandora, Internet stations, etc loses the On Screen Display and everything must be seen on the receiver's front plate. The music information as song as such is displayed on the on screen display but no music modes or information related to the receiver output or such. I thought it glitched at first but seems this is normal to need to read the receiver's front plate display for any receiver output information as music mode, or format, and channel information.
Not sure if this is normal but Dolby Surround sounds phenomenal!! Using it on a stereo input, it sounds nearly as clean as listening to stereo but with surround sound. With all my other receivers, Dolby Prologic IIx sounded compressed, less dynamic, colored, and lifeless compared to the Stereo signal. In fact it sounds almost as good as Dolby Digital but obviously without the actual discrete channel steering. Highly impressed how much better it sounds than Dolby Pro Logic IIx(z)!!
Also with Dolby Surround, gone is the dedicated Music mode/ Movie mode/ and Game Mode. No more front soundstage width adjustment or any of that. Just one ON/OFF for center spread. Much simpler and better sounding!
I still have fine adjusting as speaker levels sound a bit off but I did copy levels over from the Denon. Perhaps internally their levels are bit different. I plan on using my Radio Shack Digital SPL Meter again.
I hated the Denon Audyssey MultEQ XT on the Denon, it made music harsh, bright, crappy sounding. I tried for a month to make it sound good but gave up and setup everything with Radio Shack SPL meter and tape measure. Sounded great again, like the previous Denon AVR-3803. Not sure about this AccuEQ w/ AccuReflex. I've heard good and bad. My brother in law hated Audyssey MultEQ XT on his Marantz also and calibrated as I did. I'm thinking of just leaving the AccuEQ off and not adding stress fighting with it to make it sound good when it sounds so good WITHOUT it on.
My only important question is why no On Screen for Network music or is this just the way it is?