...got the PK2 DIY I scored a deal on yesterday. Very nicely packaged...little black velvet back, 2 pairs of foamies, and the cable is definitely an upgrade from the stock PK2. Interestingly enough, there is no writing on the shells denoting these are/were PK2...so I suspect they are another animal altogether.
Straight out of the bag and plugged into my X5 and I wasn't too impressed. They sound nice, but don't have the same clarity and reach for bass that my Blox M2C have, or my well-burned in, ancient and trusty genuine PK3 do. There is something restrained/veiled about them.
I left them hooked up to a radio station last night at a mildly unpleasant volume and let them burn in while I slept. Going to have another go at them at work today.