I've used both the on ear Senheiser phone and Bose as well as the 450 Sens.
Here are my thought.
1. I've got large ears and the Bose get uncomfortable after a while. I do some long international flights.
2. The sound pressure from the ANR on the bose is high enough to be noticable. I really got to hate it.
3. Not sure if they fixed it, but Bose is useless with a dead battery.
4. Sen had pass through for all the headsets.
5. I find very little value in the talk through.
6. Volume control on the 450 is good and I use it and Ipod touch on most flights.
7. Bad part, the 450's I had just disappeared on the last fligh. My fault, but it would have been nice to get them back. $500+ with the headset and ipod.
I'm now going to have to replace them again. I'll buy another set of Senheiser's. I prefer the algorithms they use to the Bose.
I'd really like to get a set I could use for when I"m flying the plane and when I'm in the back. So far, haven't found anything that meets my requirements for size, portability, etc. Guess I'll keep the on ear Sen's for the front and the 450 for the back.
I"ve also had Westone custome ear plugs and they work pretty well. with the good transducers, they provide excellent sound, but there is no ANR there, only a passive cancelling. They get lost faster than the headsets.
My wife has a low end set of Sony's in addition to the on ear Sens. She likes the fit of the Sony's and uses them most of the time.
Hope this helps