My wife and I just sailed on the Liberty 10/12-10/19 Eastern itinerary cruise. Although this was not our first Carnival cruise (we had sailed Carnival twice before), we have been exclusively sailing RCCL for the past 10 plus years. We booked this cruise because the deal was too hard to pass up (we were able to get an Oceanview Suite for 80% off).
Our overall opinion (based on somewhat RCCL biased experience): the Liberty is a nice ship and this was an excellent cruise. I offer the following list of pluses, along with a few minuses.
What We Liked: