I flew KE 777's twice last year, ICN-MNL and back both times in C, this was before all the Business Plus stuff. The flights were three class at the time, with a mostly empty F section. As far as I can tell, F and C seemed to be really similar in seat width, pitch, and service.

Compared to my LAX-ICN segments (on 747's) the seats were quite a bit more comfortable on the 777's.