I'm just back from a 2-night pre-inaugural "cruise to nowhere" on LOS. As far as I can tell, it's pretty identical to Freedom of the Seas -- which means awesome!
It's amazing to me that the ship can hold so many people, yet I didn't see huge crowds or lines at any venue. Plenty of seating in the showrooms, no long lines at the buffet, etc. Embarkation was relatively painless, too.
The ship is great fun, with lots going on at all times, wonderful facilities, attentive service, huge fitness area, etc. I wish they didn't charge extra for things like Pilates classes and other fitness related activities.
I'm ready to sail on Liberty for a whole week...