I have both. It was noticeable improvement immediately. To me it was the next step up in the audio chain. I have not used it with DSD yet. The highs have less glare, while adding more subtleties to the highs and midrange. The bass seems similar to the BDA-2. When I inserted the BDA-3 it was very shocking to me. James downplayed the BDA-3 so I did not expect such improvement. It's as if you get a new preamp,speakers or amp and you listen to your music collection all over again. I am hearing more information that I never heard before.
I am using the BDA-3 along with BDP-2 with the new sound card using AES. I'm sure everyone results will differ along with their opinions. Hope this helps.
I did keep my BDA-2 and BDP-1, just moved it to another system.
Cheers,
BJ