My wife and I did the Venice to Barcelona cruise with 11 friends. We have cruised quite a bit and can make a valid comparison with other ships. What I will report will not be positive, so be prepared!
In Venice we took the shuttle bus the ship provided at Piazza Roma. It was a short ride to the dock, but the bus left us off about 250 yards from the place where you check in. There was a lot of luggage to drag and no assistance offered by Celebrity --they really should take notice of this
When coming on board we were greeted with a glass of champagne--nice touch, but beware. The next time I was offered a drink by Celebrity, it was at the Venice "sail away". The bill for these two drinks came to $15 dollars! Not a very nice touch or were they trying to get even for the free one?