Design & Build Quality:
I think this headphone is one of the most beautiful headphones on the market. When you hold it in your hands, it feels very well made with good quality materials. Everything feels expensive (they are actually expensive too!). B&O has always focused a lot on the design of its products and this one is no exception.
This headphone is not meant for everybody.
The sound is flat but well balanced. The mids and highs are very clear but the lows are almost absent (almost no bass). Compared to Sennheiser's Momentum, I find the Momentum to have a clearer sound but less wide sound stage than the H6.
Many people may not like flat sound, since nothing is pronounced and it can become boring after a long period of listening. I personally prefer a warmer sound.