Like Shakey, I've been enjoying my K&K since 2003 too. I built it as a kit. I've also added the two upgrade kits.
About a month ago I installed the new Lundahl LL1931 step-ups and they are another excellent "step up".
If anyone gets the new transformers, I highly recommend using the "reverse input" break-in method running a CD level source for 100+ hours through the transformers. I had mine attached to my office system, kind of like a "one tap" TVC. I could hear the sound change quite a bit over the break-in period. A low level moving coil source might never break them in well.