We did the 7 night roundtrip on the August 6 sailing. We are a family of 4 (kids 5 and 9), joined by a whole bunch of in-laws for a total group of 16 passengers. In order to get adjoining staterooms, we had to opt for lower ocean view rooms (2171 and 2175). This is our 3rd cruise, but first on Celebrity.
The ship itself is great--opulent but classy, no cheap kitsch. A very nice size too, as it offers the big ship amenities but not so huge that those length-of-the-ship walks become an exasperating chore. Infinity is over 5 years old, and needs a slight makeover. Not shabby or dated, but if you look closely you can find little scratches and stains and dents. But this is a detail; overall the ship looks great.
Our staterooms were roomy, well-laid out, and comfy. The bedding was fine, but the chairs looked a bit worn. The daily service was friendly, thorough and dependable. You get a fridge, but it's full of mini-bar stuff, so you can't easily keep your own water/soda cold.
The crew was very helpful and polite. I did not get the dismissive, disappointed looks I've received in the past when I pulled out my soda card. I'm told room service was always speedy and tasty (our teenage traveling companions ate pizzas before every meal). My one service complaint is that it was hard to order a beverage in the buffet, or at least it took some effort.
The food was the best I've seen on a cruise. Occasionally wonderful, usually good, and only sometimes "off" in some way. A good mix of classics and the unexpected, and very ample. We ate in the SS United States, which is well worth the $30 if you are into dining. The food was just a bit better than the dining room, the big difference being the ostentatiously grand service. Plus it has the quieter, uncrowded, unhurried feel of dining in a fine restaurant.
Complaints. The shows are apparently not Celebrity's emphasis. We had 4 shows from the song/dance team. They started weak and got better, and the final night was up to the level of, say, our Princess cruise from last year. They were plausible entertainment--not bad--just not something you'd want to see again. We had 2 comics (one standup and one ventriloquist) who were, likewise, funny enough but not tremendous. The comics each did one night, and another night they reprised on a shared bill. The other entertainment was lounge acts--a guitar-and-syth duo; a pianist I didn't see; a cello and piano team. They were enough to liven up the lounges at nights, but not the highlight of the trip.
Celebrity's marketing. There is a push to sell you stuff. It seems that this is endemic any more. But it was less offensive than what I saw on Princess last year--no shameless and trashy piles of t shirts in the nice common areas. The one time I thought Celebrity was overreaching was on glacier day, when everyone is crowded on the cold weather decks beholding the glaciers. We were repeatedly offered hot chocolate--a nice touch at 10 am--except that it only came in $10 souvenir mugs. Moreover, there are no self-serve laundry facilities. We certainly don't go on vacation in order to do laundry, but we have found that you can pack a big "wrong" and the option of doing a load or two is handy. We declined Celebrity's offer to do our laundry for $29 per bag.
Embarkation went very smoothly. The ship was delayed coming in, and we were put up in the convention center for a few hours waiting. Disembarking likewise was smooth. We were probably the 6th or so group called, were told to gather at 8 am, and we were off the ship by 8:30.
The kids program was well received. The facilities are not real big--maybe a couple thousand square feet. But the kids seemed to have a great time. The last day included a well-attended talent show by the kids.
The spa was very nice. I heard good reports on ladies' services, and the health club was well appointed with equipment. No TVs to watch while exercising, however.
Our stops were Sitka, Juneau, and Ketchikan. These are familiar stops and we did very typical routines at all three. Helicopter onto a glacier if you have the money and the inclination. My general advice would be, either plan a good shore excursion or stay on the ship. If you just "get out and walk around" you will mostly see tourist merchandise of a low order.