The last "stereo" receiver I owned was a NAD 7130 (still in service at my son's house!) Ironically, Peter Tribeman was instrumental in the design of this classic unit. After that I started using AV Receivers (Pioneer, then Denon, and then separates). Prior to this I used a variety of stuff. My personal favoritse were Dynaco pre-amps and Dynaco ST70 amplification (2 channel).
My most recent method of listening to vinyl was to use a Parasound phono pre-amp feeding my Lexicon MC-8 pre/pro and then amplified by two channels of my Outlaw 755. In the short time I've had the RR2150 I have to say that listening to records on it sounds just as good (and even quieter!) than my HT setup. I don't know whether this is because of a better phono pre-amp in the RR2150, or the lack of all the digital stuff, or a combination of both factors and others that I'm not mentioning. Considering that my HT electronics pre/pro and amps list for about $8000, I consider the $600 RR2150 to be very impressive indeed.
And it's not really fair to try to compare it with "legacy" devices because of the advances in circuitry over the past 20-50 years.
The bottom line: For 2 channel sound (and to bring a tear to the eyes of an old-timer) the RR2150 has to be heard to be believed. And, since I understand that it is temporarily out of stock, the secret is probably out.