It depends ...
I flew the 747 on the upper deck and the A340-600 recently and of course I was more excited to fly the 747..
However the business class on my 747 flight was fully booked and the lunch service took forever ..
I liked the service on the A340 more ...also one of the lavatories was quite big even had a window.
Id say the LH business class experience doesn't differ that much when it comes to aircraft type , but rather crew, load factor etc..