Hey Patrick,
Well, I never was that much impressed by the Perf. Art pieces I saw, but I'm not really able to remember what they all were.
The Sarpaneva moon disk on the HM3 is an interesting addition but it wasn't a revolution.
The "out of stock" watch I liked was the diamond panda riding the HM4. This one was really nice and poetic.
I'm must say I'm more into regular MB&Fs as they are already Perf. art in a way...
Thanks for sharing your thoughts
Mark