LH C seat is not as bad as a lot of people claim. I'm 6'2 and not at all slim, but I sleep okay in it. It's not brilliant, but it's okay.

LX new C are very nice, but at the end of the day, does anyone have a proper nights sleep on a plane anyway? I normally get a few hours fitfull snooze but it's hardly what you'd call refreshing. Even the NZ, Virgin style beds aren't that brilliant.

My advice would be to go on whatever flight time is shortest and spend the hours you save sleeping in a bed on the ground...