We've been cruising for more than 10 years, taken 12+ cruises, and this was the second one on a Celebrity ship. We chose the cruise because of the itinerary and the positive experience we'd had on the Celebrity Century years ago, which we thought was first class. The Infinity is a nice size ship, not too big, and it was clean and the staff was friendly. That said, for the money they charged ($4500, which didn't include internet service @ $324), the entertainment was hopeless and the food was terrible. There wasn't much of a selection for entertainment or activities. Food quality, selection and service in the main restaurant was average, and food served on the Lido deck was the same EVERY day both for lunch and dinner, with the main entree being roasted pork for 10 out of the 12 days (there must have been a great sale!).
Our cabin was a nice size and the steward was friendly and helpful.
Favorite ports included Vancouver, Victoria (Butchart Gardens was a great excursion), Seattle and San Francisco.
Overall cruise was nice, but the quality of Celebrity cruises has gone down.
Not sure about the cabin category, but the room number 9000. The room was in the very front of the ship on the ninth floor, and while it didn't have a balcony, it was larger than most ocean view rooms and very quiet. We were pleased with the room and with the service we received.