The satay in F is the same as in J. It's available on most J flights, including a short hop between KUL and Langkawi I did earlier this year.

The only time I've flown in F on MH was the A380 and while the seats were a bit worn and tired, they were huge and comfortable. The service was easily better than BA in my limited experience; there were only two cabin crew for the cabin, but there were only 5 of us in there.

The food in general is pretty much the same in F as in J. The Malaysian dishes are better than the western ones.

You might also want to check out the MH forum, not just for this, but because AFAIK they are refurbishing the lounges at KUL.