For me the LX seats are way too narrow. LX has 2+2+1 across in a 777. Other airlines with a similar layout have 1-2-1 (seats are 25 % wider with aisle access from every seat and much bigger box for your feet). I am only familiar with the AC seat on the 777, but my clear preference would be AC for the seat. The :LX food and service might be somewhat better, but for me the seat and the ability to sleep is the most important aspect.