Having towed our company's 7000 lb rated utility trailer close to fully loaded with the following vehicles, 2011 Ford F150 3.5 Eco Boost, 2012 Dodge 1500 with V-8 Hemi and now a 2012 Ford F150 with 5.0 V-8. The Eco Boost towed the best when in the hills due to the turbo, then the Dodge with the Hemi then the Ford with the 5.0. All three had gears that were very close. Both Fords with 3:55 and I can not remember what the Dodge had but it was very close. The Eco Boost and Hemi both had around 65-70K on them the 5.0 currently has 68K on it.
Never had any turbo problems with it and it currently has around 156K on it. The Hemi has around 165K on it and is now used for close by stuff no long trips or towing. On every long trip or attempt to tow it throws check engine codes, and results in a trip to Dodge for more wasted dollars. It also had the softest rear springs out of the three.
Good luck on what you pick or do.