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.
The good:
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.