How well does it work with the noise canceling turned off? I have some Lightspeeds, and sometimes I forget to put in new batteries on long trips.
According to the manual, it will still work fine in passive mode, even if the batteries fail. Does the Lightspeed unit actually not work at all without battery power?
No, it actually works great, but it looks like the ear pads are much bigger than the Bose, so I was just wondering.

Oh- i thought you were asking if the mic and headphones function without battery power.
Obviously, the noise attenuation without the ANR system active is lower... but it's still pretty good. Can't find the specs on attenuation in passive mode for the X, but it's probably not quite as good as headsets with bigger ear cups and tighter fit. Without even comparing them in flight, I'd wager that the passive attenuation is as good as, if not better, than my Telex 3000.
But the comparisons I've read suggest that compared to, say, the Zulu, which also has Bluetooth, etc (the X doesn't even have an audio input), the X really only gives you more comfort for the extra money. Bose did score slightly higher in intelligibility, but for a lot of people, if it attenuates as much and has extras like Bluetooth, at a lower price, then it's a better deal.
I'm paying only a little less, with the discount, for the Bose as I would for the Lightspeed... but I can't get a Lightspeed on a casual payment plan.
