We have mainly traveled on Royal Caribbean before, they have been our Go To company for all our cruises but when we were invited by friends to go to Alaska with them - Celebrity was the choice as RCI doesn't specialize in that region.
We have been on both the larger and smaller ships, i'll comment on a few specifics.
We had a concierge class balcony on Deck 9 - mid ship.
Stateroom: Bathroom much larger than on RCI, but at the cost of stateroom size, getting around the bed was difficult, you had to constantly pack and unpack things because of zero floor space and no couch, just a uncomfortable chair thing in the corner. Ordering room service was a pain - there was nowhere for 2 people to put it unless you were on your balcony -- which isn't always an option especially on an alaska cruise. The room was very nice - wood appointments, lots of storage and closets and things everywhere, but 3 closets again took away from floor space.
Island Cafe (Buffet): The food here was above average from the buffets on the other RCI ships, normally we skip the buffet, but on this ship it was both spacious, with tons of seating, lots of food options, custom pasta and omlette stations were great but did take time and patience. The Sushi was great the nights they had ACTUAL sushi (Hamachi on a buffet! but was otherwise a vast amount of veg rolls, it's a cruise I wasn't expecting much. It was consistently good.
Main Dining Room: This was disappointment, VERY inconsistent, normally I expect a quality of a decent chain steakhouse - not here - there was some highlights, the appetizers were ok, the french onion soup was pretty bad, no onions, and constantly inconsistent, if there was one thing we could count on, it is that you didn't know if what you ordered would be good or bad. We did send back a few things (or just get something else). The entree's were "fine" - they slice their meat REALLY Thin, steaks are 1/4" after cooking as a result a medium rare steak was almost always over cooked. The service was as expected, with great wine service but slow regular drink service. Normally I don't ask for drinks they just appear, but here a 15 minute wait was the norm.
Murano: The specialty restaurant on board was OUTSTANDING - the best I have had on any cruise - we went twice, once for dinner and once for lunch, amazing staff, amazing food, amazing experience, quality, attention to detail on every plate. Amazing Risotto, Beef, Lobster, every dish we had was perfection. This was the highlight on this ship.
Entertainment: It was ok, the comedian was "fine", the elton john impersonator was pretty pathetic. I didn't go to much else. The best entertainment was the guitarist Jessica in the Cova Cafe, I could get a drink, hang out and listen to her play. It was a good time there.
Bar Service: Find a good one - not all had great service, the ones that did were amazing, found the best service was normally AT a bar, and not in a lounge area, because this cruise had drink packages they made you work for your drinks - so walking up to get a drink was the norm. I found the bar tenders at the Rendezvous lounge were the best. The Hemisphere lounge which sounded like a good idea was horrible, great view, location and idea, except understaffed, filled with people reading books shusshing you, slow service, and the "teen" club was next door with cranked horrible music all day and kids screaming. Repeated calls to guest services netted nothing.
Kids: Not many kids on board - the ones that were you knew about, because the ship had so little kids activities they played everywhere, in the halls, the elevators, all over the ship. I was run into by 2 kids on wheelie shoes twice. Parents get a grip, teach your kids some manners.
Pool Service: If you like pools and hot tubs - stay far away from this ship. The pools and tubs close EARLY. Nothing open past 10PM. Both days at sea, the pools closed at 4pm until the next day -- Yes read that again - 4pm on a day at sea. Here we are - AT SEA - on a small ship and you are closing all the pools at 4pm???? This wasn't a mistake or some kind of health issue either, because I was told this was normal.
Hubbard: We saw it, up close and personal, captain got us as close as possible, the weather really played ball so we got some great views. Captain made a good call getting us in a little earlier which was the right one because the fog came in and washed it out. So good job there.
Room Service: as expected
Embarkation/Debarkation/Tendering: VERY fast and efficient, faster than most ships. Bags showed up fast. Rooms available quick.
Casino: Fine, but short hours.
Overall: I had a "Fine" time - but was a little disappointed, this was a bit of a test for us if Celebrity worked for us - but I don't think it did. The ship "shuts down" at 11pm, there is almost no night time activity, I've never seen a ship that closes down stuff as much as this one. Sorry guys, we are sticking with RCI.