I'm in. Searched this thread, I'm the only on here with K450 in my arsenal? Very amazing sound out of these headphones. I only wish that I could find the special adapter for the end that plugs into the headphone, so that I can make a custom cable or two. Plus, the cable is detachable for no reason, since they shelved the bluetooth adapter project.
I also have:
-K240 Studio - First AKG I bought. Amazing sound. Bass as good as any of the DJ headphones you see in stores (Sony, Memorex, JVC, etc)
-fuchsia K518 LE - $36 on ebay, ridiculous bass! Fun to listen to, but can't be wearing glasses with these
-K316 - the over-ear clip keeps them on in a motorcycle helmet, but they don't block out all noise like IEMs would
I also bought my girlfriend a pair of JBL 430, which are amazing, despite the looks. Man, they have punch. They have as good sound as my K450, but a little less analytical. This, strangely, allows you to hear the separation between instruments a little better. They're actually the first headphone I bought, on clearance for her because she only had the free earphones that came free with music players, besides being a fairly serious musician. I was so impressed with the quality that I ended up learning about AKG and becoming a convert. Have been overall impressed. I even bought my little brother a pair of new old stock K27i that I found for $30. For the first time, he can stand on-ear headphones. Besides one pair of Ultrasone and one pair of Sennheiser, I'm an all-Harman headphone guy.