I seem to recall the CO website showing a 12" seat recline on DC10 and 757 BFs, but 15" on the 777s and 767s. I've flown all but the 767s, but never close enough in time to really compare the difference.

One difference I do notice is that the footrest seems to be sturdier on the 777 seats.

Also, the cappuccino on the 777s (and 767s) is a nice benefit!