I did UA1/2 a dozen of times in C and while stretching my legs walking through the Y cabin I have never ever seen anyone who looked comfortable and relaxed in those seats. And to my surprise the flights were always almost full. C is bad enough for this trip length but it's the only way to go. Good thing on these planes there are no window shades, there still is a little light coming in through the darkened windows. Otherwise it would be 18 hours in a completely dark tube. Now that's torture.