Personally i will never fast travel in Skyrim because of the beautiful enviroment and its going to be a part on how i RP. I used to fast travel all the time in Oblivion because nothing exciting ever happened when i would walk from city to city. Dragons in Skyrim change that for me. Now while im walking im going to have to be on the lookout for those winged-beasts. And the fights against them are unscripted so they could swoop down and attack at any time.