The boarding process can get a little frustrating only because there are so many people trying to board at the same time. You will have that with any cruise, I'm sure. As soon as we were on board we were greeted with a glass of champaign. From that point forward, we were treated like royalty.
I HIGHLY encourage everyone to purchase an all-inclusive drinking package. It was so convinient and you didn't have to worry about a huge bill at the end of the cruise.
We chose an interior stateroom because it is cheaper. It honestly didn't matter because we didn't spend much time in our room. There was so much to do on the ship. Everyday they had different activities. I was completely content watching the activities from my lounge chair by the pool. That being said, if you want to lay out by the pool for the day, GET THERE EARLY. Though there is supposedly a rule that you can not "reserve" seats, many people will do it by putting their towels and bags there- then go wander around the ship. I guess if you can't beat 'em then join 'em :).
The food on the ship is incredible. They had the option to purchase an upgraded meal experience, but the main dining room is honestly better than just good enough. The food was some of the best I have ever had. The service was above anything I have ever experienced. They honestly treat you like royalty on this ship.
There was only one negative to the whole trip- and it's a tiny one. There aren't clocks ANYWHERE. They give you a schedule of events for the next day every night but it's hard to keep track of time... so bring a watch!
I promise that if you choose Celebrity you will have the vacation of a lifetime. I'm cruising with another cruise line in Feb (not by my choice) and they REALLY have a lot to live up to. I doubt I will ever have an experience like that one.