I've rang the thing all of twice.

1) BA A320, during the safety demo, the fold down monitor near my head didn't stop folding down, going back up, back down, etc. That just needed to stop right then before the motor burned out.

2) AA 767 DFW-LHR. Stuck in middle seat after misconnecting, can't sleep. Both aisles snoring with me thirsty. Sorry but the FA can bring me a drink without waking anyone up- I can't say the same thing about getting out of the row. (Perhaps that I remember this says how strongly I work to stay in aisles at all times?)

I always feel like a bother when I consider using it, though, even in F.