While it was hard not to compare (and unfair as well since, to me, the Allure is an impossible act to follow), I thought the Navigator was a beautiful ship in its own right. Even though we went from a balcony on the Allure to an inside on the Navigator, the second cruise being a bargain cruise I found on line to keep us out of the Canadian winter longer, we were pleasantly surprised at all the great areas to sit outside on this ship and didn't miss the balcony at all - well, most of the time :-)
The room was spacious enough, with even more storage room than the Allure balcony cabin had, and the pools, mini golf and fitness centre were great. The ice show was excellent.
We only ate in the dining room twice (we had My Time Dining) and enjoyed the casual atmosphere in the Windjammer or the Cafe Promenade for something to eat in the evening. Breakfasts could be busy in the Windjammer and a couple of times people asked if they could join us but we enjoyed that since it was nice to meet others.
I would have no hesitation taking another cruise on the Navigator. Really the only negative was that the disembarkation was very chaotic and took much longer than expected.