The F suite is identical on all long-haul CX aircraft. So is the service. The 747 has its good and bad points (not really worth going into here), and it really is misleading to say that it is better than the A343 or A346 service in any substantive way. I say that after having dozens of flights on both types and having sat in just about every seat in every F configuration. There are 12 F seats on the 747 vs 8 on the A343/346 so there is more square footage and open space, but it isn't like most other airlines that do have different service levels on different routes. Pick the route and time that suits you (or more to the point, where there is seat availability).