I actually still have about 10 of these left from over 2 years ago. I also just stuck one in the fridge last week, guess I'll crack it open this weekend and see if my findings compare to yours Arrowhead. I recall opening one last year and I thought it kind of gone downhill. The thing about brett is that is goes up and down with age. If you don't like it one year, try it the next it could be a lot better, the year after that it may suck again.
I did however find that the Enigma's get much better with a few years on them. I have one left from what I think was the 2006 brew. I opened one last year in the winter of 2011 and it was fantastic. I bought 16 of the 2012 version and have opened two so far. They were great but I am pretty sure with atleast a year of aging they will be much much better. I'll let you know how this Golden Ale has held up.
Edit: Just cracked it open. The brett funk aroma is still there. Head retention is low but the bottle also gushed a bit upon opening. I think this is aging pretty well. Still has some nice "orange" citrus notes to it and the brett has obviously worked its magic quite well on this beer. There is a slight medicinal taste to it though. I'm sure it's phenols from the belgian yeast, or the brett. But they are quite plasticy/bandaid like.
P.S. as always, NG did not even reply to my email. They are definitely not homebrewer friendly like other breweries. I also, never did get around to attempting a clone of this either. One of these days...maybe.