I've had my Bose X or 3 years and they've been great. Recently had to send them back because the ANR was cutting out and they replaced the ear muffs, head cusion, both yokes (the service tech found some fault, I have no idea what it was), and remote for free. 5 days and they were back to me.
Several people at my company have the Zulu's and have had to return them (several times in one case) for ANR issues. The Lightspeed customer service is excellent as well, but the longevity of the Bose is legendary.
However, if you have bigger ears, the Bose may not be as comfortable, since the Zulu's have a much larger ear cuff, and therefor are a bit heavier (I think).
Passive noise reduction on the Bose is useless, however, if the batteries fail the headset still works, not the case with the Lightspeeds from what I've been told.