Tangentially, it's actually really hard to find good headphone reviews anymore, let alone headphone demo places. Pro music stores (like Guitar Center, Sam Ash, etc) are probably the best bet these days - but they tend not to carry headphones like the high-end Sennheisers that used to be my favorites (HD570 I think?).
AFAICT, their noise cancelling headphones still have by far the best noise cancelling. If you work in a noisy environment or fly frequently, they're amazing. If your primary concern is audio quality in a normal or quietish environment, buy cheaper headphones (or I suppose more stylish ones, if that's your jones).
I actually just got a pair of very expensive Jabra Evolve 80 headphones (http://www.jabra.com/Products/PC_Headsets/Jabra_EVOLVE__Seri...) primarily for their mic. The noise cancelling is dramatically worse than Bose and the headphones make me look dramatically stupider because of the mic. But clients can hear me better so that's a net win.
I wonder if Bose is doing something beyond noise-cancellation in the QC25s when you turn them on. It sounds similar to a BBE Sonic Maximizer, as if they've licensed the algorithm and tweaked it to the characteristics of the drivers in the QC25s (which sound lousy when the headphones are turned off).
You bring up an interesting point that there's no real center in the U.S. that carries audio gear online, Europe has Thomann (thomann.de) that basically carries everything but now in SF it's hard to find something else then B&H Photo Video NY to deliver stuff.
I'd say the audiophile market is a more resilient to style than the general population, but not completely. Flat response headphones, like the AKG-701's are reviewed as not being "fun". The thing is, audio mixing plays a much larger part in your experience than headphones. After owning the 701's, I would much rather choose different cheaper 'colored' headphones for different genres, than use a headphone that is able to reproduce sounds more accurately. YMMV.