I've test driven an Aviator, and if you have the bucks, it's a sweet ride. In fact, I test drove an Aviator and a V-8 equipped Mercury Mountaineer Premier back-to-back, over the same roads, in the western Detroit suburbs I live in. I spent about 30 minutes driving each one (the dealer was cool to let me out by myself with some pricey rides too!!).
While the Moutaineer was a nice riding truck, the Aviator, built on the same platform but with different suspension components, more attention paid to sound insulation, and a different (and dare I say better interior), the Aviator was a dream.
If my eyes were closed, I would swear I was in a sedan, not a truck. It rode as quiet and smooth, over some bad tar strips and broken pavement, as any luxury sedan of any make, but it handled much more nimbly. Not quite an LS, or 5 Series Bimmer, but not at all truck like, and way better than the Mountaineer (which handles better in my opinion than nay other mid-level priced, mid-sized SUV of any make, and that includes Toyota and GM).
For weather like NYC, the Aviator, if you get one with the best seats, is great for another reason:
heated and cooled leather seats, with adjustable temperature settings. That rocks. In the winter you warm your butt, and in the summer when you've been parked in the sun, the driver and the passenger, at least, get to cool their seats off. My understanding is no other SUV in it's class(and same applies to the Navigator) has them.
I only wish MY budget allowed me to buy one!!