Our first time on Celebrity ships, and a very enjoyable one it was. The crew were unfailingly polite and good fun, the cabin staff were cheerful and friendly, the cabin itself was a very good size and had all we needed, and the food was absolutely splendid.
We had a bit of 'excitement' in the Israel stops, thanks to the onset of hostilities, but everything was handled with professionalism and most people were entirely unaware of the tricky military stuff starting to brew up.
The ship's own shore excursions couldn't really be faulted. Lovely tour guides, comfy cool coaches, did exactly what they promised.
We had a spot of bother with their "Celebrity iLounge", which alleged to be there to help passengers with their IT connection problems. We met with many exhausted fellow passengers who had queued in vain for several days, on and off, with no luck at all. Definitely something Celebrity need to sort out, given that most people have internet technology with them these days and might need to take or make an occasional message. My own problem (top spec new Windows phone) was met with "Oh it doesn't work on this ship" (after a long time queueing both days). Good job I had other technology available, really.
But goodness me that's one very small grumble in what was otherwise absolutely wonderful stuff.