While Guy Betsy might be right on some aspects of the F meal services in regards to quantity, I think LX F beats LH F anyday because of the much higher friendliness and better attitude of the flight attendants. Also, I like the LX F seat much better than LH F.
The new A340 has one major improvement, the entertainment system aside. There is a small "hallway" going across the front of the F cabin, so there is no "slalom" anymore to get from one side to the other. Also, no disturbing fellow passengers anymore. I loved my F flight on the A340 the other day on LX. IMOP slightly better than LH F, but food really is more and sometimes better on LH. I also miss La Prairie, plus I don't like the amenity kits.