This was my 4th cruise (3rd with Royal), and probably the least enjoyable of them all. That's not to say it wasn't fun, it was just hard to compare to the others.
We are 2 mid-30's adults, and we were travelling with a 6 year old and an 11 year old.
The Liberty of the Seas was a nice ship - not great, just nice. Nothing to complain about at all. It was well taken care of, clean, and spacious without seeming overly large (being the second-largest class of ship in the world, that's a positive).