I'm going the other way. I have an early build Aviator that is the worst vehicle I've ever owned quality wise. I've owned six Lincolns since 2013, including four brand new, factory ordered top-line SUVs. The fit and finish keeps getting worse and worse. One of the rear doors doesn't open anymore, and since they are e-latches with no emergency release it looks to me like the interior will need to be torn apart to fix it. My dealer is also terrible, so I will wait until I send it back to tell them about the door - they would butcher the interior and probably add more squeaks and rattles.
I will say that the best quality of the Aviator is the powertrain. The 3.0 twin turbo (400 hp, 415 lb-ft) and ten speed are really impressive.
I am about a month away (hopefully) from my GLE 450 showing up so I can't give a comparison yet, but I would recommend you beware of the Aviator.