NCL Getaway or navigator of the seas?

My wife and I are looking to book a cruise over my birthday. Right now we're debating between the NCL Getaway or the Navigator of the Seas (both 11/27/16 for 7 nights). The main thing we are wanting to do is relax.

We have been on 2 RC cruises together before (Enchantment and Oasis), and I have been on one before without her. At this point, I feel like I have a pretty good idea of what a RC cruise is like. Additionally we are crown and anchor members. Neither one of us has ever been on a NCL cruise though.

After looking at the costs, we've determined we can get both for about the same price (including drink packages etc.) so the upfront costs aren't really an issue.

What we're wondering about, is how bad upcharges and hidden fees are on the Getaway? It seems like there is a lot to do on that ship, but a lot of it seems to cost extra (i.e. specialty dining, magic show, adults only area etc.) Also how bad are the crowds? We've been reading that the crowds can get pretty bad in some places.

As far as the Navigator goes, we're worried that there wouldn't be enough that is different from other RC cruises that we have been on (i.e., it look like all the same specialty dining, same activities etc). Also it looks like there aren't a lot of outdoor/open-air areas when compared to the Getaway.

Has anyone been on both? What are your takes on the two ships?