| OP: In the end it will come to personal preference
Biking outside
Pros
Scenery, nature
Tougher workout, sweat more
Cons
You have to find a path ( shouldn't be hard if you live near the valley / mountains )
Half way through you can't just say " oh Im done, good workout" you gotta finish it ( more like a pro ? )
Can't watch tv ( if can watch tv and understand whats going on your not peddaling hard enough lol )
And inside exercise, is pretty much the opposite. Though it is nice to know you can jump off the bike and be 10 steps from the shower. | 
