I tried to book a return MAD-TRS flight with LH miles for 15.000 "fly smart" I was shocked to learn that apart of miles LH charge 204 EUR!!!!! for taxes.
So if I choose LX for same flight I pay 158 eur for the whole ticket, without giving away 15.000 miles!!! LH is getting mad. They have earned 1.1 billion euros last year, and are charging full YQ taxes on free tickets!!!! Time to think...