I would love to see horse stamina. Since people run their horses all over. If they tired out, then people would hav to RP a bit more. It is frustrating when someone just has there horse runing full speed to get from the market to the bank, or something similiar.
or you could just roleplay anyway and have your horse walk slowly ... dont know the words for different horse speeds :S (trot? canter? :S)
thats what i do anyway - its much more fun to walk around slowly than move at full speed - plus people tend to attack you at random less if you arent going at full speed.
I do this is as well, infact I have frustrated a few soldiers by making my whole army go that speed when we are all mounted xD
I suggest it, so I don't have the eyesore of fools going full speed through a city, and on the open road. Horses shouldnt be worked so hard unless neccesary. I of course do RP that way, however it would be nice if it was a system.