Sorry, but you're wrong about the QC20s. They do, in fact, have "active" noise cancelling. I have been using a pair for at least a year, and they are great.

Sorry, but you're wrong about the QC20s. They do, in fact, have "active" noise cancelling. I have been using a pair for at least a year, and they are great. I actually prefer the QC20 noise cancelling to that of the over-ear versions I tried (which were either QC25 or QC35, I don't remember).