I used to think the same and tried to upgrade from old C to F whenever I can. Now I have flown new C/F on five straight five transpac trips, I simply just dread paying for old C and then cough up SWU just to get lie-flat seat.

It is just a personal preference, really! I love window seats and want access to aisle to walk around during the folight, and also F suite provides more storage space for my notebook, camera, Iphone, books, etc......the new C just don't have the space and easy access of the old C.