I forgot to reply back to this thread until square_wave messaged me (thanks!).
I did manage a comparison of sorts.
I compared 1) Lyngdorf 3400 powering my speakers (network player, dac, pre, amp, room correction)
against the
2) Coincident 300b with Lyngdorf 3400 as its network player, DAC and pre and room correction.
I definitely preferred option-2 which says to me that the 300b is better than the Lyngdorf digital amp for my speakers.
Option-2: gave the deep bass of an SS but also the alive and rich sound of tubes with good extension amongst the highs and lows.
Option-1 sounded a bit more dull and un-involving in comparison. 300b SET amps do justice to their reputation for sure.
Amp vs Amp, 300b certainly beat the class-D for the music I listen to (Indian classical, jazz, middle-eastern instrumental).
I have just bought a new Network-Player/DAC/Pre combo which is being shipped to me as we speak, that I will soon compare against the Lyngdorf to see if it can beat the Lyngdorf/300b combo.