We sailed on Summit 8 years ago. In most areas, the ship is unchanged. The public areas were clean and in good conditions save for the bathrooms that do need some help. Overall the food was good, but not to the previous standard. The cabins are looking pretty dated and the bathroom in ours needed a refurb as did the cabinetry overall.
Food -- the buffet had many choices for breakfast and lunch. It got a bit repetitive but it didn't take much effort to come up with a tasty B/L. It does get crowded at peak periods especially on sea days.
Main dining was good. Only had one marginal to poor dish though a couple of nights the menus didn't really appeal. You can always go with a basic steak or broiled salmon as a fallback. Service was generally prompt and courteous. Our usual waiter did a good job of steering us to the meals most likely to please.
Overall cleanliness was apparent. Only in a few places did Summit look ragged. Mostly in bathrooms.
The mediocre -- entertainment during the day was limited. The ladies in our party missed the craft activities they enjoyed on Azamara. Evening entertainment was good with the exception of one comic/impressionist who was just awful. It's difficult to believe anyone on Celeb actually had seen his act. Back to 1940 Joey....
Embarkation was not as smooth as some lines. The lines were long and the staff we dealt with weren't that adept at checking us in. Port Liberty is nothing to write home about. Just a warehouse with shuttle buses and a taxi rank outside.
The passengers were very old in general and a large percentage were barely ambulatory. This led to very slow moving lines whenever a show or dinner let out. And as one nice lady said "old people can be among the most rude". There were several hundred on board who seemed to think they were on a private yacht. They'd knock you over to get on or off the elevator regardless of who's turn it was. Wait in line in the buffet? Why when you can just push in front? Stop in the narrowest spot with your walker to decide where to go next or have a conversation? Sure. No one else would like to use the aisles.... Shout into a cell phone instead of going outside? Why not?
Wonder if any line has the guts to run "no walkers/scooters" cruises? Probably uneconomic...
The bad --
Tendering was a giant cluster ----. We had 2 tendered ports and both times Celebrity ran things poorly. They tried to blame their issues on weather etc, but the glaring problem was incompetent organization. For example, instead of having a check in table at the top of the auditorium where we were sent to wait, they put the table on the stage such that the entire geezer population had to trudge all the way down to the bottom, up on the stage, back down again and then out. They only had one guy directing all this the first day. Couple that with poor English skills and an elderly clientele that can't half hear and it was a nightmare. In the first hour we sat waiting to get off in Bar Harbor, they managed to move just 98 people out of that huge line. Another ship was in port at the same time and their tenders seemed to move twice as fast.
Of course, what was really going on was they were getting those with paid excursions off first, but they didn't have the courage to just be honest. Finally they got all the tenders working and got rid of the line by noon -- half the day shot.
These 2 experiences lead me to wonder how they can possibly handle 3000 people on the new class of ships...