While I don't own a pair of QC15/25, I do have my own pair of Sony noise cancelling headphone that somewhat does the job.

How's Cathay's longhaul headphone in Premium Economy? I notice they are noise-cancelling too. But obviously they won't be the same pair found in J/F.
http://www.cathaypacific.com/cx/en_U...omy-class.html

Are they half decent? Or should I bring my own pair?