They say these horses are hearty and strong, but they seem to be sluggish and move very awkwardly. Even Clydesdale horses can run with some finesse and agility. The jumping is also very weak. I kinda hope they work on that. In addition, I would really like to see the different breeds have different attributes to them, such as, speed, stamina, strength, and even willingness to fight or flight.
Yeah, the lack of variety in horses is disappointing.
I've gone back to playing Red Dead Redemption, and I was blown away by the huge increase in quality with the horses. They move faster, they take more hits, they move realistically, and they actually are necessary.
I understand Bethesda not wanting to force us to get horses, but they could have at least made them appealing. So far, here's my pro and con list for horses:
Pro:
They come in a variety of colors
They're slightly faster than you are
They have little to no regard for the laws of physics
They're pretty inexpensive
They allow you to circumvent carrying capacity
Cons:
All the horses (save two named ones) are completely identical stats wise
They get killed often because they run headlong into battle with little regard for what it is they're trying to kill
You can't interact with the world while riding them, and the time it takes to get on and off them is considerable
You can't name them
They aren't that much faster than you, and unless you pay no regard to stamina when you level up, you'll soon be able to sprint much further than they can
No first person view
They aren't all that impressive to look at
You can't really find any in the wild
All in all, I find horses to be more trouble than they're worth in the long run.