Yeah, D is improving and will offer high quality amplification at lower prices eventually. For now, I don't think it can keep up with the best class A amps, tube or SS, but it's close and getting closer everyday.
One thing about D amps is it seems they require more tweaking to get the sound right and they react more strongly to changes in wiring, caps, etc...
Re that Leak amp above, Solen caps combined with Duelund...
Might try the Clarity TC caps there instead.