I am on my 2nd lease of a Big Horn with the V6 Pentastar. Previously I had six Ford F150 leases, XLT's and FX4. All the Fords had V8's. If I were to drag race the V6 Ram vs. the Ford F150 V8's, I suppose the Ford's would pull away near the end of the quarter mile, but up to about 80 mph, I'd say it would be about even.
I have found the Ram to be the superior truck in every regard. It is astounding how much better it is. I would have never thought so when I first looked at them over three years ago. I was a Ford guy through and through. The only reason I changed to Ram is my lease came up the year Ford went to the aluminum body and they were asking an arm and a leg for a lease deal. So I went to Ram.
I use my Ram for hauling payloads of up to 800 lbs. It pulls nicely, I don't even notice I have anything in the bed. I've never towed anything with it, so can't comment on that. I've had 3.21 gears in both and I like it for the gas mileage on the highway.
My wife has a 2016 AWD Charger with the V6 Pentastar. No problems whatsoever with that car. I think the Pentastar is a fabulous engine. I remember reading the literature three years ago and thinking, "Man, these people at Ram are really proud of this V6 engine. What's the big deal?" But having had two trucks with that engine I can say that I totally get it now.
I had a thermostat replaced in my 2015 at about 25,000 miles. Otherwise no problems.
I've had my 2018 for a year now, only 9,000 miles. The only thing I've noticed is a small water leak into the cabin area which dripped from the overhead console into the floor console. Maybe an ounce of water total. This was during a rare January thunderstorm in Minnesota. Others have said the gasket on the cab mounted brake light could be leaky. All I know is it hasn't happened again and my truck is parked outside almost always.
The last three F150's I had all had a leaky gasket around the cab mounted third brake light. There was always debris and/or moisture inside the lens cover. After the first two were fixed under warranty, I didn't bother with the third one.
If you get the 2018 with the 8.4 UConnect sound system, be aware that Ram pushed a software update last September that screwed up the equalizer in the stereo making it sound extremely bass heavy. They've since fixed it--took them eight months--and my stereo is sounding great again. People with the 8.4 UConnect with Navigation are still waiting for their fix.
https://www.ramforum.com/threads/uconnect-software-update-received-whats-in-it.126015/
May I ask why you are opting for the 2018 vs. the new style 2019?