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 entertainment was good, 'up in the air' was a circ du sol type of show, the main show, Saturday night fever was good but the main singer wasn't up to the show's multiple set broadway sing and dance style.
The comedian was only on for one show, not sure why they didn't schedule him for smaller venues as I saw he was still on the ship attending other shows. in fact it was the on thing carnival did better, they had four comedians rotating through club sized venues.
The cabin was good, we had a mid-ship balcony. It's a bit larger than carnival dreams' cabins and had twice the balcony size. I really liked the touch screen terminals that provided interactive directions to any cabin or venue on the ship.
embark was swift and easy, debark was the pain it always is, bottle necked by the customs desk. We were on our way at 10:30am.
In summary, excellent ship, could use a bit more variety of entertainment but I must say royal Caribbean has converted me.