So I had the QC II and got them exchanged 2 times for poor ANC after updates out the box. I got asked if I wanted to upgrade to the 700's for an additional charge of £50. I obliged and recieved these late last week. Now am I the only one who thinks these look cheap and plastic? And the ANC is no where near as good as pre update on the QC's?
Nc on zero actually amplifies the external noise to make it sound great when on 10. I
I won't get into an argument on whether the N/c is better on the NC700s (although I do think that's the case), however I do feel a lot of people misinterpret the Noise cancelling levels. Levels 0-10 is not about just how much noise it cancels out, but how aware you are of your surroundings. Hence 0 isn't that there is no noise cancelling but (as you said) amplifies some sounds around you so you can be safer in certain circumstances. I hear many people complaining that others walk through the street with their headphones on and their eyes on their phones, and this is a way to counteract that.
So I don't see them as having done that at level 0 to trick you into thinking level 10 is fantastic. There is a setting in the app that you can use to turn N/c off, and it would be better to use that as a comparison.