"Have you listened to any other Class D amps than the Spectrons? "
Hello Claudle.
No, when I was shopping for new amp (I had McIntosh 2102 100wpc tube amp and I feel I need more power and finesse for my - at that time - WATT/Puppy 8) I was searching mostly among "muscle" class A amps. By chance somebody recommended Spectron and I have read very interesting professional reviews and then started the thread here, identical to your and...I end up very happy: Spectron was much better then any class A (and some tube ) amps I tried. Not to mention 2-5 times cheaper...
Later on, a few friends brought to my system their class D amps. I don;t remember any name besides Bel Canto Ref 1000 Mk2 - does not matter to me because none of them was even in the same class.
I don;t remember if there was NuForce Ref 9SE but I looked their web site: Ref 18 must have greater peak current and I would guess noise filtering then Ref9SE. How much it changed the amp overall- your guess is as good as mine
All The Best In Your Search!