To start....we were told there would be two formal nights...there were three, which annoyed us because we were prepared for two.
For the most part, people did dress in smart casual. Some outfits were smarter than others but only a few had on tee shirts. One night I saw two men refused entry. He had on shorts, Hawaiian shirt and flipflops..one had on some band shirt and jeans. I liked that they were turned away.
As the cruise went on the dress became less smart on the part of the men. The women, except for some late teen females, were dressed very well. Suits prevailed compared to tuxedos and some Scots wore formal kilts, which was interesting as I have never seen a person wearing a kilt save for the NYC st. Patrick's Day Parade.
Personally, I liked the overall cruise except for the formal nights. I would have prefered to wear a dark blazer and an open shirt. I do not find it relaxing to put on a suit and tie, eat a full meal , walk around the ship then go to the later show. Also, the Glaxaxy had no alternative real restaurant, except for the Bistro, which allowed "come as you are". We ate there once but the food was only "fair'. One night it was hot all over the ship so I changed to shorts, polo shirt and wore that to the 9:15 show. No one glared. I was cooler and comfortable and that is what mattered at the time. As the show went on , it got hotter.
I enjoyed the Celebrity cruise but hope in the future the "smart casual" becomes the prevailing dress code and if one wants to wear a tuxedo, suit, dinner jacket etc then may at their own discretion.
Also "smart casual" is open to interpretation. Some men wore plaid button down shirts, others wore long sleeved solid shirts. some , like myself wore outside the pants dressy camp style shirts, some wore Izod type shirts , some hawaiian print shirts etc etc. What is smart casual in Iowa isn't the same as smart casual in NYC or Boston. I think " business casual" is a better term, but I do'nt own a cruise line, so I will follow smart casual
just my nickel's worth