I drive the 2012 Max Payload (a.k.a. HD) / Max Tow and it handles my 8k trailer well and is fine around town. My neighbor has a 2015 Ram 2500 with the Cummins. I prefer the electronic steering on my truck and I also prefer the height on my rig (his sits several inches higher). I thought the ride on his truck with the coil springs was fine. The engine is smooth and strong, but I did not get to tow with it. I would expect the Ram 2500 (gas or diesel) to tow better than my truck due to the heavier weight and components. For that matter the 2500 diesel would be no contest.
If I were buying a 2015/2016 truck there are 2 things about the new F150 Max Payload I do not like as well as my 2012. I like the fact my truck weighs 6,000 lbs as that provides stability. The new version is 700 lbs lighter. Also, the last time I checked you could not get bucket seats in the Max Payload package and that is a feature I really like. If it were me I would take a Ram 2500 for a test drive and make sure that includes running on some roads that were not too smooth to get a better feel for it.
Good luck,
Stu
