I have to concur with thborchert but would add a little to this - and it's all about your own personal comfort. Too many buy headsets online or based on someone else's recommendation instead of trying them for size.
I went to my local retailer, intent on buying a Sennheiser S1 passive - I didn't want to spend more on an active headset. I then tried it on and it felt "perched" on the top of my head - no doubt after a few hours flying, it would have felt "the norm" but as I was there, I tried out all the headsets he had. The DCs really felt as if my head was in a vice. No wonder the passive performance is so good if the headphones are pressed with so much force against my head, but at what price? Headaches after an hour?
I tried all headsets they had there - more than 30 different brands and models - including active with a sound generator to compare the performance and my personal choice, the headset which fitted me best, was the Lightspeed Zulu. I tried to rationalise not needing active, not needing to spend so much money, but once I'd decided to splash out for active, I also thought about spending a bit more to buy the Bose as a few had said it's active performance was "years" ahead of anything else - but in the sound chamber, I couldn't hear ANY difference....
Also, reading various forums, I'd heard about the poor customer service from Bose when discussing defects, I'd also heard about how good Lightspeed is, that defects, even out of warranty, were repaired without cost. So, I'm not here to say "this is the best, the others are also rans", I'd recommend everyone to try before they buy. All I can say is that my Zulu.2 headset is not an "also-ran", but for me the optimum headset.