A Must-Have for Frequent Flyers!

Since I do a lot of flying, this pair of headphones is an absolute godsend. I tried out the Bose QuietComfort II as well as the Sony MDR-NC11, and I think the Sennheiser beats them both for a variety of reasons.

Size and portability:
The PXC250 is definitely easier to pack in the briefcase than the big Bose. The unit itself can be folded neatly into the carrying pouch that measures 7"x4"x1". The pouch comes with a side pocket for batteries and adapter - or a small MP3 player. The Sony is quite a bit more portable than the PXC250 but it trades performance for size.

Performance:
For a semi-open headphones, the sound quality is excellent. The noise cancellation works beautifully and effectively on planes and other environments with low frequency background noise. Since the Bose QuietComfort II is a closed headset, it inherently blocks out more outside noise than the PXC250. However, once the noise-canceling circuit is engaged, the Sennheiser can almost match the Bose's canceling capabilities. Once the music comes on, the difference in noise canceling between these two units is almost insignificant as far as I am concerned. The sound quality on the PXC250 is great though not as clean and crisp as the Bose, but the difference just does not justify the extra $200 for the Bose.

Compared to the Sennheiser, the Sony unit is very weak in noise cancellation and it lacks the power as well.

Comfort:
I have actually worn the Sennheiser unit on a 9.5hr flight from Munich to Toronto. I actually fell asleep with it on my head and I did not feel any pain or unusual discomfiture afterward. The unit is very light and big enough to fit on my big head without a vise-like sensation. On the other hand, I find the Bose unit very uncomfortable to wear for long periods of time and there seems to be no way to avoid the dreaded "sweaty ears" problem with the QuietComfort II.

Battery:
The battery unit takes two AAA size batteries and they last forever. I think I must have used my first set of batteries for at least 30-35 hours before I had to replace them.

Cost:
I got the unit from Ebay for less than US$100 and I think it is worth every penny of it.

Cons:
-The battery unit is just too clunky and unsightly
-The unit could use a volume control on the battery unit or in-line on the headphone cable.