If you look at the seat layout, they are very different.

The JAL 777 has nine seats in first, three each row. But due to how the seats are designed, combined with how they were installed, the seats are very isolated from one another. The design is such that the seats have a very wide area to the side of the seat that really prevents you from effectively communicating with the people next to you. The installation is such that they are staggered a bit, adding to the privacy. It's not like they are in the EK or SQ suite style, but it is much more difficult.

The BA 747 has five rows. Rows 1, 2 and 3 are 1-1 because they get into the pointy end. Rows 3 and 4 are 1-2-1. The two in the middle are next to each other and, to a certain degree, point towards each other. It is much more conducive to interacting with the person next to you.

Look at seatguru for the BA configuration and you will see what I mean. The JAL configuration can be found at http://hiro2s.com/JAL-W71.htm