See the poll. I'm curious.
I used to fast travel everywhere, but when I swooped my saves away and started anew, I made the policy not to fast travel. My Nord warrior has fast traveled only once, when I was too bored to walk from Halted Steam Camp to Whiterun. But otherwise, the 26 hours on him are completely fast travel-free. I even go to High Hrothgar on foot when need there be.
I use carriages and that boat in Dawnstar a lot, though, but I don't count it as fast traveling since it was obviously meant to be in the same way there were silt striders in Morrowind.
It's really more rewarding to play like that, and I've discovered many new things and all in all it feels like there is more to do when I'm not just blitzing through every quest and faction.