I'd think you might want to consider a few things:

1) equipment - 747 would be preferable in my book ^ for the intimacy and privacy of the forward cabin

2) flight time - you'd want a long enough flight to sample different meals :-:

3) time of day - an all-night flight where sleeping time takes up most of the flight wouldn't give you as much service from the f/a's as a daytime flight

Have I missed anything?

Cap70