My wife and I were kind of the opposite. We tested a nav and then a plat expy. We were initially looking to see if the nav was worth the extra money. We went away feeling the nav was the better buy for the money. It's true, to get the extra goodies like bluecruise(which is now standard on standard trim for my23), massage seats(fantastic), heads up display and 29 speaker revel(fantastic), you had to spend an extra 10k, but to get the nav outfitted like an expy, its actually cheaper than all the premium expy trims starting and you get more stuff in the nav. The spp (and kr) expys are even more expensive then the platinum, just for the power upgrade and nothing else. Our problem was we couldn't find a standard new nav, which was less than all the expy plats we found, and even then, lincoln wanted no words on discounted prices. The standard nav is only giving up the massage seats to the expy plat, but for late 22, ford wasn't selling any plats with the feature. Nav comes with more standard features and upgrades out the box. Expy mainly has a cheaper stereo upgrade, but to be honest, to our ears, we both thought the 14 speaker revel is better than the 22 speaker b&o, which was important to us. You also get cooled second row seats and the 13in screen interface is better than the 15in interface in the expy. The ride in the nav is a bit better too. Lastly, the interior material quality blows the expy away. The build quality is really good, but my wife's biggest disappoinment with the 22 expy, she felt our 18 expy had a better feeling interior and the main reason for wanting the nav. However, if you want the lwb version or tow, the above doesn't apply, which we didn't need either. I also realize that for my23, lincoln jacked up all the pkg and std pricing for nav, I'm talking specifically for my22s.
I would've liked to get a 22 nav, hell a 22 expy, but we rele do love our 20 nav, esp now during this trip. I love(and missed) how quick the navs ride quality puts my passengers to sleep. The expy wasn't so cosseting in the ride department.