Reminds me of the helmet no helmet threads.
Pretty much comes down to the horse, the terrain, the distance, speed, gait, and personal choice.
I use boots as a spare tire, but my horses are steel shod. Riding with boots doesnt work fo rme.
just this. Every horse on the farm is barefoot, Even the racers that run at the track(and win) all summer get their shoes pulled and trail ride all winter barefoot. My mare has the best feet on the farm. In the summer we ride on gravel, rocks, sand and through mud and grass. The first 6 weeks of riding are fine, but as we pick up the distance and pace, I can wear her feet off far quicker than she grows them. When we get close to level with her sole(usually by june) she gets shoes, or I would have a lame horse. We can wear through a set of steel shoes in 4 weeks, so thin the farrier folds them in half.
The 'recreational' horses are barefoot all year round, they only go 5-10 miles 2-3 times a week.
One horse on the farm has bad feet, brittle walls and a permanent crack. To stay sound for regular riding he needs to be shod. This is genetic, and the crack the result of an accident. No suplements will fix this, he just NEEDS shoes.
I've never had a good time with boots, but if they work for you, great :)