I've heard the same improvements the previous posters mentioned from my Duelund caps, tx2575 resistors and a recent upgrade from stock ceramic power supply caps to Z Superior caps in SBAM.
Natural timbre of Duelunds, increased resolution of tx2575 and Z Superior caps have created an amazing sense of realism, performers are simply in the room with me! The Duelund's natural timbre evokes much more relaxed listening sessions, even with digital I want to listen for hours on end. I can't wait to get my Merlins up to a full compliment of Duelunds, towards that end I have a pair of 6.0uf tweeter Duelunds on order, should have them installed in aprox. 4 weeks.