Mariner is also my favorite ship. I have also sailed the Navigator; although only once. What you lose are the two restaurants - Signatures and Prime 7. You also lose coffee bar area, larger computer area, and the Garden Promenade. What you gain are larger cabins and a more compact ship. The Cat E cabins on Deck 6 are fantastic and very convenient. Unfortunately, I believe that Navigator Cat E are more expensive than Mariner Cat H.

I would sail on Navigator again; however, I would much prefer to be on Mariner for the additional restaurants, lounges,and Garden Promenade/Coffee bar.