If the horse can handle it, I like barefoot. Any horse that does go barefoot gets biotin and sometimes another hoof supplement, just in case. I've had some though that do need them. One mare had a riser on her left front and pads in front and if she wasn't shod every four weeks, she would go dead lame. I had asked the farrier and the vet about it, but she was quite literally perfectly sound when she was shod properly.
I like ponies barefoot a lot too. Most ponies are hardy little things and one of my biggest pet peeves is when people buy a barefoot pony and think it looks better at shows if they have shoes. i don't understand that connection :)