Amazing sound and durability, just a little bit too rough at the touch.
The sound of these strings is seimply amazing, definitely the best strings I've ever used under this aspect (I've been playing for about 26 years so far).
They also seem to be very durable. I live in the north-eastern region of Brazil, where the climate is extremely humid. All the other strings, except Elixir Nanoweb and Optiweb get rusted in one week or less! Now I can add the NYXL to the short list above. I put them on two of my guitars about one month ago and they still sound and look new. I'm not sure whether they last as long as the Elixir, but they do last certainly very long.
The only reason why I gave 4 and not 5 stars is the tactile sensation: they feel a little bit rough to my taste, definitely much rougher than the Elixir Nanoweb I've been using in the last years.
These strings are the perfect upgrade from 0.09. The upper strings are not so thin like 0.09 and not so tough as 0.10. Have good playability and the NYXL quality. I highly recommend.