Got mine yesterday, and when I plugged them into my Penguin amp, they sounded especially fantastic. This is my second pair, but I never got to enjoy the first pair because a friend tried them with his iPod and would not give them back (I had so many other phones). He paid me for them, and when the group buy came along, I had to get them. They aren't all that much behind the PK1s, in fact, especially for the price difference, when both are amped.
Anyway, I believe the PK3s are the best value in SQ/price bar none, including the legendary Ksc75s, which I own too (and Kramer modded them). I mean, if you compare durability, form factor, SQ, etc. The PK3s rule!
Oh, I used my homemade donut pads (a cheap leather hole punch works perfectly), which is also what I use on the PK1s. Haven't tried the full pads. Will get to it someday.