Mine are barefoot and have no issues and we ride everything from sand to mountains. If they are having no issues then I reccommend you keep them barefoot. I had asked a clinician about shoeing and he said if you don't have to then don't
I rode my horse daily and had to shoe every 6 weeks. Eight weeks was too long and I NEVER had a horse that comfortably went 8 weeks. I also rode so much (and part of this was on paved roads) that the shoes wore out and could not be reset (I rode a LOT).
I learned how to shoe my own horses too. I shod them and reset.. did the boreum (when I used it) and everything until I was injured (not injured from shoping the horse). I could not shoe my own horses after that and had to hire it done. I still would reset a lost shoe.
Shoes were the most expensive part of horse ownership, but I rode so much they had the be shod.