Originally Posted by
BuildingMyBento
I've flown in J a lot, and if those lie-flats help at all, it's merely for the day I land. For every successive day, I might as well have flown Y (and most of the time, do).
I would agree on the whole, but it can be quite useful to be able to function when you first arrive unless you can transfer easily to a hotel or other place of repose.