I am struggling to get rid of some of mine.
I tend to fly between LHR and GLA so the benefit is minimal, but when I get a poor seat, I'll use a GUV to get closer to the front.
I tried to use one tonight in the LHR lounge and the lovely lady moved me to 1C, then after checking and finding there were no meals, gave me the GUV back with a wink. I then nicked a packet of crisps from the lounge to compensate for lack of food, but when onboard, a bmi chicken dinner was found from somewhere.
All in all, not a bad result.