These are fantastic headphones, no doubt about it. I'm actually pleasantly surprised by Bose's $400 pricing for the 700 headphones. They're only $50 more than the $350 Bose QC 35 II and Sony WH-1000XM3. The company could easily have charged $450 for these things, considering the new design, new premium materials, and better noise cancelling for music and phone calls.
Still, $50 is $50. And I often see both the QC 35 II and Sony WH-1000XM3 discounted down to $300 — a $100 difference to the Bose 700 $400 price tag.
But there's one feature that sticks out and makes it easy to recommend the Bose 700 to a certain group of people. If phone call quality on headphones is important to you, especially in noisy environments, $400 is the price you need to pay. No other headphone I've tried comes close to the Bose 700 for phone call quality. With that said, maybe the Bose 700 will, one day, also get discounted later on in their lifetime.
If phone call quality is a minor thing for you, and you're really after audio quality and great noise cancelling to hush the world around you, you'd be happy with the $300-$350 QC 35 II or WH-1000XM3. Those slightly older and cheaper models are fantastic wireless noise-cancelling headphones — and if you own those either model, I wouldn't be rushing to buy the new Bose 700s. Unless, that is, you want the better quality phone calls.
But, remember what I said about the kind of audio you get with the Bose 700: clear and good is a given, but they're also a little conservative and less exciting and/or customizable than the Sony WH-1oooXM3, at least right now around launch time. I'm not sure yet how well Bose's upcoming equalizer option will work, but it could inject a little more excitement to your listening.