My husband hates the lie-flat seats. He doesn't like that there is no leg rest when sitting up straight. There is foot rest, but it's not attached and awkward to stretch your legs out to the foot rest when eating.
He also say the seat is hard and uncomfortable. The seat is at an angle when flat, so he can't lie down straight. The padding they put down for the international flights really doesn't make a difference. In a separate aside, I know I'm being nit-picky, but it grates on me that I spend so much money for they seat, but have to put on my own padding.