Outside is SO MUCH EASIER. It's more fun - I'm a nosy house checker-outer, so I like to see all the gardens and x-mas décor and window boxes and wreathes and peek into people's well-lit living rooms in the a.m. as I jog past. So much better than a screen on a treadmill.
Yeah, hills suck and humidity isn't very cool, but a nice tailwind is always lovely.
