I use my horse just to get say from Whiterun to Riften and help me carry some loot. It is very tedious to drag loot from a non-city to a major city.
Maybe I should just leave the loot behind? But really they give the player a little bit of relief, I would say and I think most players make it on foot mostly, so being in an area you visited before and killed everything, sure a horse is ok.
But leaving your horse at the Whiterun stables, he shouldn't just show up at some cave 10 days later near Riften. For me it was ok at the time, I had sooooo much loot...but he shouldn't be there at all.
Horses are good for loot-transport, your char's feet are better for discovering stuff. Found a couple of caves quite near Whiterun today, just by walking/running. Still needed the damn horse to go back to town
