Short follow up.
I used the N9s on two flights, both in the 4 - 5ish hour range. On the first, I listened to a little bit of music on my Walkman and then some movies streaming from the in flight entertainment. On the way home I used the IFE only to watch a couple of movies. I stuck to BT and did not use a corded connection.
Comfort
One of the main reasons I wind up having a lot of abandoned headphones is not necessarily sound quality - it's comfort on longer flights. Whether it's the cups, how it feels on the top of my head, or both, it matters. I was pleasantly surprised by the N9s. Perfect? Definitely not but for the first time in some time with full size headphones on a plane, the top of my head was not sore. On the way home I wore a baseball cap and had to adjust because I had accidentally placed the headband on the button so that was pushing down on me.
The left ear was slightly problematic but not bad in terms of needing a break at some point a few hours in.
Overall, no major complaints in the comfort department. Compared to my older Technics EAH-A800, they're definitely more comfortable especially at the top of my head. Comfort is the main reason I was looking for something else as the SQ/NC on the A800 is good enough for travel.
Noise Cancelling
The NC tech has come a long way over the 20ish years I've been using many different headphones on planes. On the way out I sat just forward of the engine and on the way back I was in the exit row. They take care of the low end rumble fairly well. Will they block you out in a complete cone of silence including filtering out human voices? No. If that's what you need from a pair of NC cans, these are not the ones you are looking for. On a plane where you want to reduce the roar of the engine and keep volumes reasonable to listen to music/movies? They'll do the trick (as will many others).
I really do think we've gotten to a point of "good enough" NC from most vendors, especially in the $250 - $400ish range. A big part of it for me has to do with fit, and these did pretty well there for me, too. Even wearing glasses, I didn't feel I had to keep adjusting the ears to get a seal if I moved my head.
Sound Quality
My impressions of the SQ are pretty much the same as earlier. They are musical cans and handled movies surprisingly well. Even using the EQ on my Walkman worked well with these. If you feel they are too V shaped (I didn't), you can still EQ other things in to your liking.
Pairing with Multiple Devices/Multi-Point
On the leg home, I had the N9s connected to both my laptop and the phone. It detected and switched between them without any issues.
More Summary Thoughts
I like the N9s. I am sure there are others that are both better and worse at all different price points. I only wear them on planes, so spending way more on headphones I use a handful of times a year is not a smart investment for me. I always go for tradeoffs in terms of comfort/sound/NC and these do a great job of all three. Are they worth $399 US? Maybe. It's a competitive landscape in that price range and everyone's needs are subjective. I've tried and/or owned enough headphones over the years and it's a tiring quest to find ones that work for me. I'm hoping these settle in for awhile.
