Pooks, this may help. My first bike when returning to bike riding was a mtn bike. I took it out on the road and although a good workout (maybe too tough) I couldn't get far from home and therefore didn't really enjoy the ride that much. I decided to get a road bike. I quickly went from 6 mile rides to 12 miles and then to 20. Within a year I had done my first metric century. I honestly believe the road bike will make riding more enjoyable and therefore you will ride further and longer. You'll get further away from home (or wherever you start) so you will see more interesting things and have more variety in your rides. And we all know that "Variety is the spice of life."
As we must account for every idle word, so must we account for every idle silence." ~Benjamin Franklin