I would hope a free internet service is not as good in resolution as a $300-500 personal bike computer and GPS. (or without the GPS for what? $100 or so. That's still not especially cheap) What something like Mapmyride (and there are others) would do for you is give you a preview of a ride. A bike computer, better resolution aside, means you have to ride the course before you know what you are getting into, which is not always what you want.

Mapmyride is still reasonably functional, serves a purpose, and it's free. But honestly I only used it in my post because the OP said she was using it.