Go take them both for a test drive, you really can not go wrong on either. As others have mentioned the Pro's for the Ram is it's newly redesigned and has a new 6.4 Hemi with cylinder de-activation on highway (only HD truck that offers this). So if this truck is a highway daily driver that might offer some sway.
I test drove the 1500 series Ram and really liked the interior styling and chair comfort more than my old mans 2012 F150. It's my understanding the interiors are pretty similar in the dodge between 1500 and HD models, not sure on the Ford trucks.