Boots should be fitted correctly and used when needed. An ounce of prevention is worth a pound of cure. I learned this the hard way but you don't have to! I recommend soaking boots (I like the blue Davis boots best as they hold up to use and have more stretch and flexibility than the more expensive Easy Boot Soakers.) You can buy Davis soaking boots thru Valley Vet for the best price and fast free shipping!
When it comes to riding boots I like the Old Mac G2s. They have quite a lot of improvement in design from the original Old Macs. I like the boot to fit very tight as with age and use, it will stretch. I use front boots usually but in very rocky terrain I might use hinds also. you can put studs in them, they do not impede hoof mechanism and they don't come off.
I do have one pair of Renegades. I think they are very good boots especially for low heeled horses as they do not rub the heels. They will come off though as the closures are velcro. I like buckles better. The Simple boot by Cavallo seems to be a good boot but again it has velcro. When velcro meets with mud and ice it does not work well. I fox hunt so I use boots hard and in all kinds of conditions so I don't want to have to look down and check to see if my horse has lost a boot. But I will use them because you just never know when your horse might step on something that even a hard healthy hoof has no defence, like a broken drink bottle or other sharp object like a nail in a board stiking up.
During transition, boots both soaking and riding are necessary I believe. Soaking boots are the most important for horses that are dealing with founder issues as you can insert a pad to help ease pain. Its like a mobile hoof clinic and short of paving your place with rubber mats, it's a lot easier to stick some pads in a pair of boots.