I shoe when I ride (december-beginning of summer) simply because of our climate.
Often the temperature doesn't go higher than freezing for months, so then studs are definitely needed. Going out riding without them would be suicide.
My mare is shod year-round... I wanted her to go barefoot for ages, and she always went lame so I finally got the vet to take a looksie and he said that she'd never be able to go barefoot because her soles are too close to the ground, even though she's got very strong, good hooves that don't ever crack (*knock on wood*)...
I'm hoping my gelding can go barefoot, but I doubt it because he's my mare's colt and I ride so much that I HAVE to keep shoes on my horses... My gelding will be getting his first set of shoes next year probably.
Both mine are shod for jumping and protection. Herbie's feet ware really fast so he has them on all four (when we bought him he had only fronts, but his back feet were chipped and cracked) and Nani has them on the front only.
I keep all my horses barefoot and will continue to do so. I will never put a shoe on my horse again. This is my preference, and I do understand that everybody has their own opinion, but mine are better without!
I use a certified farrier. I only shoe Riley in the summer front shoes(it's preferable in the AQHA show ring for a horse to have aluminum shoes)... It may be fad driven but... that's how the show world works. In the winter I pull his shoes and let his feet have a break.
When I was heavily jumping Pistol I kept aluminum shoes on his front feet to help absorb the shock. Black horse was used for hours on end in the rought trails and on gravel so we kept him shod all the way around but now that they are not being used like that, they are all barefoot.
Beauty is very tender footed and always had shoes. She may go back to shoes when she is back to full time use, but for now... she too is barefoot. I see alot of cracks and chips in the summer from them stomping flies. Especially with Pistol because his feet are softer. It causes me to need the farrier every 6 weeks for some and for others I can wait 8 and sometimes even 10 weeks. In the winter, it's every 8 weeks....