We haven't done Chefs Table on Celebrity but did the Magic carpet meal on Edge a month or so back.
Menu looked amazing so didn't mind the large upcharge (think it was around $300 for the both of us) but had to say it was the most disappointing meal all week and we did get a full refund.
Food was mediocre but the service was so slow.... We had been waiting about an hour before we even got our bread course, whereas tables all around us were on courses 3 & 4 (and yes, we were seated before them).
Drinks service was so slow also, so just seemed they were way understaffed.
During sunset it was a lovely place to sit and eat, but by 10pm it was dark and quote cold - we had to use our phone torches to see what we were eating.
Lovely idea, but just needs to be executed waaaaaay better.