Both are very good products and have their advantages and disadvantages.
I would recommend to try both and decide for yourself. The LH F on the A380 with the huge bathrooms is something to be experienced.
My experience would be that both have good service, but the likelyhood of getting subpar service (especially if you are not Swiss) is higher on LX than on LH, i.e. if in doubt I would take LH over LX.