Sound-wise, I can't tell a difference between the Bose X and the Zulu's but it's easier to plumb music into the Lightspeeds, so that's what I went with. The bluetooth thing is cool I guess, but you can't use it once you're higher than about 040.

If you can't afford them, any ANR headset is better than not having one. The "I'll wait until I have a real job" argument just doesn't hold water because the noisiest planes you'll ever fly are the ones you fly when you're getting started!

As far as hearing mechanical problems, I think you can hear them easier when the drone of the engine noise has been suppressed. If you can't afford an ANR headset, just don't buy a digital flight computer, expensive flight bag or a bunch of other useless electronic crap and you'll have the money.