I traded up to the PFX five weeks ago, and have flown with it over a dozen times.
I'm still not sure what I think of it. The headset is VERY well made, as befits its breathtaking price. The Kevlar coated cords are nice, since we have sliced the cord on our Zulus several times.
The Super ANR is...different. It starts with normal ANR, and then kicks into "super" ANR after a length of time that varies from 2 minutes to 45 minutes. I know this sounds crazy, and I agree, but that's the way it works in the very loud back seat of our RV-8.
When it kicks in, there is nothing quieter. And music sounds amazing. But the lag is annoying.
At first the headsets didn't work for Mary at all. Lightspeed sent us an extra thick head pad, and voila, it started to work. But with the almost random warm-up period.
So, there you have it. When it kicks on in a reasonable period of time, the PFX is great.