I agree!
I have a pair of Litespeeds... And when I say pair, I do mean pair, as one of the earpieces is separated from the headband at this moment. Actually, they've been like that for about two years, as I didn't want to deal with them anymore and went back to the trusty DC 13.4's.
The difference is truly amazing between the two, but I do know that the DC's will work, and will work EVERY TIME. The Litespeed is just too fragile for regular work like 121 (not to mention that they take up a LOT of space in your flight bag, or need to be carried separately).
My other problem with the Litespeeds was only touched upon breifly, and that's "whaddya do when the batts die or the electronics take a nose dive?" Having had this happen once, I can say honestly that wearing Litespeeds with the power off is WORSE than wearing no headset at all. Maybe it's just a perception, but I think the earcup design actually channels outside noise straight into your brain... And yes, worse than sitting there with no headset.
One more thing is that they have a lot of mass out near the edges of the earcups, and are more resistant to direction changes than the DC's. You'll see what I mean the first time you turn your head quickly while wearing the Litespeeds, that "snap-back" motion of the headset reacting belatedly to directional change is disconcerting to say the least.
In the end, I'd say if you are going to buy an ANR headset, make sure it's one that has the usual passive damping if the electrics are off. At least if the electronics die or the batts die in the middle of a four-day trip you'll still have a "regular" headset to protect you. Unless, of course, you want to bring a spare headset, which is way too much hassle IMHO.