Just completed a 12 day cruise on the Navigator and was very disappointed. We had sailed on Regent before (although 20 years ago); our most recent trips had been mostly on Crystal, and our expectations were very high.
First of all, the ship is very old....definitely at the end of its life in spite of a major refurbishment just three years ago. There is a musty/moldy smell in many areas of the ship (my wife is highly allergic to mold), and there are many signs of aging, including malfunctioning A/C in many of the cabins.
Service was mostly perfunctory, at best. This may be, in part, due to the fact that this was a segment of their "World Cruise" (nearly half the ship as on for over 130 days), so non-World Cruisers were definitely second-class citizens. The staff would fawn over the World Travelers, but, other than our stewardess, no one seemed to know our names.
Nice layout, including walk in closet. But moldy smell from A/C, and difficult to adjust A/C or turn off