Pros:
It's fun!
It's scary, so I get a feeling of great triumph every time I succeed, especially when the conditions are bad.
I feel great.
I get to look like a superhero to my cow-orkers.

Cons:
It takes planning to set up my gear.
In bad conditions, it can be uncomfortable.
I don't do it often enough.

I find it funny that some serious cyclists around here ride long distances for fun or exercise but are impressed that my bike commute is 13 miles each way. That sounds like a lot to them. The difference between their ride and mine is that mine is useful. So usefulness makes a ride seem longer? Isn't that funny?!