I'm delighted to say that I now own a BDA-2, paired with the BDP-1 I purchased nearly two years ago. And I'm loving the results!
The most obvious (and I do mean obvious) change is the 3-dimensional soundstage the BDA-2 delivers. In the past, the soundstage from my system was always 2-D -- left to right. This is the first time my setup has ever produced a soundstage with depth, in particular extending back behind my speakers (MartinLogans).
My experience is consistent with the reviews I've read saying the sound is moved back (recessed) with the BDA-2. But it's not a negative when it's delivering that 3-dimensional sense of musical space. The music still has plenty of toe-tapping energy and drive, with both pop/rock and jazz music.
Initially, there was some harshness to the upper frequencies. I was sure the fault lay with my system, which has a tendency to tip into over-bright territory. Yesterday I swapped out the XLR cable connecting the BDP-1 to the BDA-2, and that seems to have solved the problem. I listened continuously for about 90 minutes earlier today with no fatigue.
My old DAC was neither old nor cheap, but the BDA-2 is superior to it, and the differences are not subtle. A subtle improvement is all I expected -- hence my delight with the actual results.