I have travelled many times between the UK and Germany, mostly with LH, and speaking as a passenger with a bit of inside knowledge, I found them as good as anyone else. As far as making mistakes is concerned, a while ago I'm sure the captain's sidestick on a LH Airbus was connected in the reverse sense which would have caused the loss of the aircraft were it not for the actions of the FO in recovering the situation. So their engineers can make mistakes (as can anyone) but this incident shows the skill of their pilots.