Wow okay I just got my second 4U LE.
Couple things:
First of all there's no room for wobble so there's no left/right wobble as described
here.
Secondly the snap mechanism sounds entirely different. It's like this silent thunk, while on the other one (and on my old XL) it's a very distinct clicking noise.
And finally there's also less up and down wobble but not by much. My old XL had the most of that.
I assume all three differences are related to the wiggle room between the hinges.
Also one question: if I format the system memory, will it mess with the pre-installed MH4U?