First year of a model is always a little bit of a dice roll, but the drive train is tried and true so I'd have zero concerns there. Jeep put together a pretty solid process just for Wagoneer customers to prevent and/or quickly resolve issues. Keep in mind when you are on a forum you are dealing with a small subset of owners and certainly ones that are more vocal. I'm not in any way diminishing any of the issues those on the forum have mentioned, BUT keep in mind people are more like to post up if they have a problem vs. if everything is going great. I too have had a few minor issues, but nothing that makes me regret my decision or caused us not to be able to use the vehicle in any way.
As mentioned above mpg would be my only negative thing to mention. My RAM with a hemi gets 21mpg on the interstate, the waggy gets 16... hell my srt jeep got better mpg than this thing got. but its a school bus with leather seats so not sure anyone on here expected stellar numbers.
GW III, 20000 + miles since December, on and off road, minor issues (dead battery once due to mud sticking to the boards keeping the electronis going all night) but so far extremely reliable and very comfortable.
Mileage around 15 - 16 crusing on road with a rooftop tent and larger offroad tires, 13 off road.
l Can't say much about backseat screens, phone connection, and other electronic stuff, which I do not have or use. The Uconnect with Android auto works fine most of time. ADA needs driver attention in curves and with oncoming traffic on narrow roads.
I you are lucky enough to get a specimen like mine go for it. The 6.4 L motor is dream.