I endured LH in Y back in January, doing JFK-TXL via MUC and return. I think they were UA codes. I was automatically assigned the worst seats on the plane as described above. Dirt cheap, so I thought "really, how bad could it be for 8 hours?".

Um, really quite awful.

I will say this however. Although LH Y is a blood-spattered nightmare onboard, I think they treat *G quite nicely on the ground. For example, I was able to use the dedicated F check-in at TXL and the nice gatefrau moved me from middle-seat purgatory to a not-bad exit row (I think just because it was free, I don't think *G have any priority for these seats).