I think for your application, The Roam disc 2 would be a good choice. Two things for you to look at. 1) The tire width. I really like the 1.95" tires on my Giant Sedona. They are as smooth and nearly as fast on gravel as pavement and appear to fit on the Roam. 2) Is the gearing. The Roam has a range of 21 - 120 gear inches and the Talon 2 from 17 - 82.
Both go low enough to tackle all but the toughest terrain. The 21 low on the Roam is about as low as practical for the kind of riding I think you will do. Its almost walking speed. I can climb fairly steep hills of gravel, Loose stone and some rocks with that in my lowest gear on my Sedona without getting of the seat.
However, If you put fast tires on the Talon, Your top speed will still be limited by the 82 gear inch tallest gear. I have available 89 gear inches which is good with a strong tailwind, Or descending hills, But I seldom use more then the 78 gear inches of my 2'nd tallest gear.