I have had my Lyngdorf 3400 for about a month now.
Its super convenient, but it has yet to wow me (except for the great bass).
I don't hear the warmth, texture, and feel like I am losing the realness and palpability and you are there moment of my tubes.
I sometimes find it a bit harsh on the highs and have to go from "Neutral" to "Relaxed" in EQ often.
The room correction had subtle effects, brought the music a bit together, but still very very subtle, so not very necessary in my room.
Initially it was quite bad, and needed break-in although the dealer said Digital amplification needs no break-in.
So far it's better than mid-fi SS but not by a lot, for me no superlatives yet, think Accuphase or Luxman could beat this amp. But for the price it is very good.
I am not giving up yet. I am going to try power cords, cleaner power, and perhaps change of speaker cables.
Perhaps it could also be because my speakers (specifically designed for tubes, Devore O96) might not be the right fit for this amp. I will try the pre-out and connect to my Coincident Frankenstein 300b to see if this theory pans out.
Will update more as things progress.
Cheers!