I use the Bose every day at work and I find them really good at noise reduction and very light to wear, none of the David Clampers I was used to. The only problem is that the ear cup holders did show signs of cracking after 7 months. I sent them back to the well know mail order shop I bought them from and after 3 weeks they managed to fix them - free of charge, but I was without my headsets all that time, it felt like ages having to use the company headsets.
To sum up the Bose are great, although I have not tried any of the other. Not so happy with the afterservice, but I could have just been a one of case? If you fly everyday, 700 quid for a good headset is worth it.