If you're still hanging around in the next little while, I would like to get your opinion as to which route you would take if you were in my shoes. I am heavily leaning towards a 3700 from BB.
My preamble: Everyone has their own preference for looks and features, as well as sound signature though once you get pass the entry level devices, sound signature should just be neutral, or transparent. Most claims of the so called sound signature differences would likely disappear in a tightly controlled comparison listening tests when no DSP (ie. direct mode) functions are used. The latter is well documented by various tests and studies but people just don't want their bubbles burst and hearsay, expectation bias, even Placebo continue to do a good job perpetuating such talks, and helped by the internet in recent year.
With that made clear, I am going to focus on objective measurements. In my understanding, subjective measurements would be fine for those who believe that it is one's ears and brain that matter, not specs and bench tests/measurements.
I do not mean to pick on the AV7705, or the SR7015, but since it was you first pick so I am going to use them for reference in comparing specs and measurements. It also helps making the comparison fair and objective because if you are now leaning on a Denon AVR, you will be pleased to know that comparable Denon and Marantz models have virtually the same design, circuitry and componentry in their preamp/DAC signal path. The main difference is that Marantz, for whatever reasons (I suspect mainly a marketing strategy) keep sticking their so called HDAM at the end of the pre out signal path. That, I believe is the main reason for their much measured higher distortions and noise. I do not have the facts to support that, but if you compare their schematics/block diagrams, there seem to have no other logical explanation.
To make it easier to read and follow up on, I am going to use multiple but shorter posts. Now let's first look at distortions+noise based on the worse of the two channels (FL/FR) measured by ASR:
AV7705........................ 0.018%
AVR-X3700H............... 0.001348%
In terms of %, the AV7705, a so called separate processor is more than 13 times higher, or about 23 dB higher.
Counter arguments? Sure, how about the contents of the harmonics, may be Marantz's distortions are mainly of the lower order 2nd harmonics. Both AH and ASR do provide the FFT diagrams so one can take a look of the harmonic contents. Let's compare the two:
You can see the differences between the two are quite significant in terms of the contents of the harmonic distortions. Most people would consider even 0.1% distortions would be below the threshold of audibility, but the question is, would you prefer one that has 13 times higher distortions/noise and it costs 50% more?
More to come..