Recently I started exploring the use of a 2 channel only preamp in my hybrid theatre / listening room, and replacing the SP3. Good as the SP3 sounds in 2CH Bypass mode, I use the room 90% of the time for stereo music listening, and wanted to optimize for music. We can get along without surround channels in that trade-off.
I'm now waiting for my turn in the BR-20 backorder queue. In the meantime, I can still use the BDA3's HDMI inputs and pass-through to the projector to show 2k and 4K video, accompanied by sound. The BR-20 will allow the same capability, although I could also get along quite nicely with the BDA3.
So for me, the HDMI inputs come with significant advantages.
Brian