hello,
some years (1999) ago i travelled from fra to bkk with royal brunei, and it was a rather unpleasant experience: very crowded 767, no possibility to sleep because of a stopover in dubai, and they didn't dim the lights after serving the second meal, but showed a lot of rather bad films. they don't serve alcohol, and stay away from the alcohol-free-rose-sparkling-wine, it is horrible.
back to fra stopover in abu dhabi: after accelerating for maybe 1km they stopped the attempt to take off, turned left to the taxyway, some mechanics arrived and 1/2 an hour later we took off to fra. this alone is no problem i think, but one week later a friend of mine also travelling back to fra told me they took off but returned to abu dhabi, and this time it took the mechanics about two hours.
but maybe it was just bad luck, or maybe they changed during the last years...