My RX-A2030 can certainly handle pre-outs for all 5.1 and dual sub. (L&R or F/R) The issue comes with trying to bi-amp externally, when it comes to time alignment and/or EQ and there is no provision made for it. Having said that, just about any commercially available AVR will suffer from low cost designs utilizing poor performing op-amps, including my Aventage. This is why I pulled all the cheap, noisy and poor performing NE5532's and replaced them with a much more robust and appropriate choice of the OPA-1612. So now I have strait shot from the ESS DAC to one OPA-1612 as a buffer, then through a second one in the Pre-Out circuit strait to the external amp input. (Yamaha M-80) This type of config opens a new arena in leveraging an AVR for very high quality reproduction that can rival any config.
Since this opens up direct download of content in its digital form to the DAC, you get the options you are seeking, like native Pandora or Spotify or AirPlay, or any other digital source really. FLAC or SACD from the HTPC can really bring some great listening.