The D2 is a good step up in sound quality from the Buesound. No question at all. I am extremely happy with the purchase and won’t need anything else for a long time I think.
Analog sounding is a good description, but the D2 is also very detailed. Noticing new subtleties in records that I know well, e.g. small reverb tails that I don’t remember being there.
With the D2, I learned that I like the sound of DSD, so I’ve configured Roon and the D2 according to recommendation from Lumin directly as below. Haven’t played around with different filter settings in Roon after that yet because it already sounds gorgeous.