I received my heretofore BDP-2 that has been upgraded to the BDP-3. I already had the new sound card in the BDP-2 so the only upgrade was wifi, the processor, power supply and additional USB inputs. I must say that I thought the sonic improvements were significant although Bryston says there should be no difference due to the sound card. However, I found that with the upgrade, the BDP-3 sounds more linear and in the mid to high frequencies, the notes sound more extended, and subtle sounds in compositions are more prevalent. I guess I am saying its more detailed. I don't know how to describe the difference, but its there. In addition, the unit seems to flatten the bass response as heavy bass compositions no longer have a boom, but rather, the bass sounds more linear and well as more extended. Its like I got free EQ for the bass frequencies.
I do not understand the technical reasons for the perceived sonic improvements, but they were indeed there. Apparently, my transducers are quite revealing as I could hear the sonic change. Surprisingly, USB from the BDP-3 to the SP-3 sounds even smoother with a sweetness I have never heard. I strongly encourage all BDP-2 owners to upgrade your unit to the BDP-3. You will not regret it.