I’m sure I’ll catch hell for posting this, but I pull a 27’ camper with a super slide and my F-150 has the little 2.7L V6 ecoboost. I had to make a few upgrades to handle it comfortably, and I wouldn’t recommend it to anyone who isn’t experienced with towing, but it doesn’t lack power. I’ve never owned the 3.5 but I can’t imagine you would be disappointed with a V6 eco boost in a full size truck. I only have 78k miles so I can’t speak to longevity, but it has been a solid truck for my needs (just don’t pay attention to fuel mileage while towing haha).

I rent cars almost every week for work.

When it comes to chosing an ecoboost versus v8 F150, I'd seriously consider the ecoboost. It drives nicer than the V8, less weight up front.

Either way I'm getting a hemi ram 1500 first.

I have a 2018 F150 Platinum Eco with 54k miles. I've had to change the rear brakes, sunroof, timing chain solenoid, and the differential pinion (bearings twice). Good thing all warranty work.