As noted, Saver Awards are capacity-controlled while Standard Awards pull from F/C/Y inventory (for First, Business, and Economy, respectively).
First and Business Class are essentially the same on the 747 and the 777, in terms of seat design, in-flight video entertainment, and meal service.
In Economy, the 777 has wider seats (by 1 inch), more legroom (by 1 inch), and better in-flight entertainment (4" personal video with nine channels and 21 audio channels). The 747 has projection televisions screens at the front of the cabin in Economy.
Business Class is a vast step up from Economy. If you can snag a Saver Business Award, do yourself the favor and do it. You will not regret it.
And order the Obento going to NRT, and the filet coming back.
777 Seats
http://www.flyertalk.com/forum/showthread.php?t=316354
744 Seats
http://www.flyertalk.com/forum/showthread.php?t=393041
2005 Menus:
http://www.flyertalk.com/forum/showthread.php?t=388704