Looks like the RX-A3050 has the same DAC for the main channels as the CX-A5100
- Professional digital-to-analog conversion (ESS SABRE™ Ultra DAC ES9016S and ESS Premiere DAC ES9006A)
As far as I can remember Audioholics had tested some Yamaha AVRs before and found their preamp section performed very well and yielded very good SNR and distortions figures.
I went from AVR to separates and found no advantage except within a year I felt (just the feeling) the prepro was becoming outdated quickly. So instead of investing another 3 to 4K on my next prepro upgrade I will likely go back to an AVR+Amp solution. I think in your case the RX-A3050 plus a good 2 or 3 channel power amp is a good alternative. It is much more cost effective to upgrade with such solution than a full blow separate system. Any AVR in the same class as the 3050 will have more than enough power for the surround channels.
If you must use balanced outputs then the CX-A5100 becomes a no brainer. Most people don't need balanced outputs for home HT applications. One more point, if you believe in Audyssey REQ software then you probably should also consider the Denon AVR-X7200W, otherwise the impressive 3050 is as good as it gets right now.
3dB is a vinyl guy so he probably cares about SQ a lot, and I think he is very impressed with Yamaha AVRs even though I seem to remember he used to think "Boutique" brand such as NAD offered better SQ for music

(I might have remembered wrong but you can PM him). I think he is one of those Yammy fan who could tell you all about why Yammy is best.