This was my first RCI cruise after having done 3 with Carnival so that's my basis for comparison. The liberty is the largest ship I've sailed on and her width made a big difference with ship motion. Even on windy days I barely felt the ship rolling. Liberty is by far the best ship I've been on. The central promendae on deck 5 is a key feature that provides a large open space inside the ship. The flow riders mini golf etc are all at the rear of the ship with the childrens areas, while the adult's only solarium is up front. This is large area with a pool and two whirl pools and it's own bar, not just a small sun deck as on carnival ships. It's partially covered so only the pool area is open above.
While it is clearly a family ship I never felt like it was overrun with kids.
The crew was awesome, service was excellent and the food was great. I went to the specialty restaurant portofino and it was worth the 20 dollars. The menu items were certainly above the main dining experience. We did my time dining, we called down daily to set our time and never waited for a table.
The cabin was very well laid out, large closet, full sofa, lots of drawers and a swivel TV.