If you search the internet, you will find problems with absolutely everything out there.
We have a 3.5 in our 2019 Ex Max. There is no turbo lag in our engine. Tons of power. It does get very hot towing our 7000 pound boat over the Rockies. And has the Cam Phaser issue which I’ll address some time this summer.
The other problem we had with this is the rear axle needed replaced last summer and it took 2 months. I’ve not heard of any similar issues on the axle.
Not sure if he eager to grab one of these with high miles. But I don’t know if I’d want any vehicle second hand with that high of miles.