I have done both and I would go for LX:
Service/Food is about equal (OK but usually not outstanding), but the new LH seat is not nice, as it offers less privacy, is too short for me to sleep well, not wide enough and the proximity of the feet and also your lower legs to your neighbors' is irritating.
The LX C cabin also offers more privacy, as there is a smaller number of seats.
In terms of IFE, although LH has a bigger screen, I was not particularly impressed. But I am satisfied with 1-2 good movies and 1-2 sitcoms/documentaries per flight, which both LX and LH offer.