As long as you are not taller than 6"1' feet you should be able to sit in LH Y. IF you are taller everything else but the exit rows will be uncomfortable. So if you are very tall E+ is way better. On the other hand I prefer the service at LH and since the A340-600 has the new AVOD in Y in-flight entertainment is as good as with most other airlines in Y.

Anyway forget free upgrades at LH. There are no free upgrades at LH. Unlike US carriers LH protects their Business and First Class cabin. If you want to be upgraded you have to pay cash or with miles.