Last summer I flew a lot (and I mean a LOT!) in various noisy light a/c. I started off the season with a Pilot PA11-26 fitted with Oregon Aero ear seals. Then about half way through I got myself a new toy- the Pilot PA17-79 ANR headset.
My 2p worth:
The 11-26 with the ear seals felt like a proper headset, very comfortable and has a nice metal headband. Fully flexible mic on a gooseneck thing (very nice feature). Cuts out quite a lot of noise, thanks to the absolutely outstanding Oregon Aero seals (I got the headband strap as well: recommended).
The 17-79 cuts out more noise with the ANR turned on. BUT (and this a huge 'but', counting in a fairly big way against the 17-79), the headband is plastic, and the way that it holds the speakers against your ears lets a lot more noise in (even after fitting with Oregon seals, and a lot of precise adjusting). The other really, really, *really*, really annoying thing is the coiled cord. AAARGH!!!! Why do people feel the need to put coils in cords?
For comfort, the 11-26 wins hands down. But for noise reduction the 17-79 is better. However the ideal combination would be the 11-26 for build quality and design, and the 17-79's ANR circuitry. If anyone finds one out there like that, I will happily swap my new car for one!