But why? Why does there need to be a variance in movement speed beyond walk, run and sprint? If you went back to changing the speed at which you run like before, you either have to make it where it's unrealistic run speed (what it has been in past TES games) or you make it so that it stays in the realm of reason but then it is so negligible there is no point to have the speed increase choice. It's a very slippery slop.
This.
I think more realistic speed would be better for the lore aspect(of course including special increases for races like Khajiit, and of course special magickal bonuses possible) and would additionally improve gameplay. Instead of running as fast as my horse everywhere, I would prefer to have a realistic difference between all modes of movement from walk, to jog, to sprint, to riding on a mount. Again, I look to Assassins Creed for those examples. Different movement speeds make the world feel bigger, more difficult to traverse, and increase my personal immersive experience. For instance, when the NPCs say it takes a 2 days journey to get somewhere, it better be half way across the map and be based on a fast walking speed. And even then, I shouldn't be able to run there in 2 minutes. At least 5-10 minutes IRL would be better.