The looks are cool... but crap, my ears really do hurt after about 5 hours of normal listening! Ya, I know. That's NOT what NS-10's were designed for.
THE REAL STORY(maybe) NS-10's were originally designed for extended listening, and Yamaha basically came up with a pretty crappy monitor that delivered super flat frequency response with very little depth or warmth.
LAB RESULTS Woofer cones constructed out of cardboard. Wow? Sure sounds like cardboard? Cool. Result? Frequency response as flat as a cardboard box! Ya, these are awesome.
THE MARKETING SPIN Imagine a Yamaha Marcom employee saying "Hey, lets tell people if their mixes sounds good on these babies, their mixes will sound great on anything!" Pure genius folks?!
PURE VANITY Clients sure think they look cool!
CONCLUSION If you want to A/B your mix, use your car stereo, the boom box you purchased last summer for $60, or your home stereo. The result? A great mix you'll be happy with, and an extra $350 bucks to pay your utility bill over the next 6 months.