The QC15's are generally used as the reference headphones for professional reviewers. When I was searching for my pair, tons of review articles I read would state something like, "these brand X headphones are great, but compared to the unbeatable Bose QC15 reference headphones, they fall short on x, y, z."
I've had the QC15's for a few years now and they are awesome. I put them on right after sitting down in my seat on the plane and I don't take them off until the door opens to depart. Since doing this, I have not had any ear popping issues either. I don't know if this is mental or not, but whatever it is, I'll take it.
I also gave a pair of QC15's to my nephew to replace his broken Beats by Dre Studio headphones. He loves the QC15, and says they are much better than what his Beats were.