My horses do fairly well barefoot and we do get them trimmed regularly. We finally found a farrier that does a really nice job. My gelding, Moe, has cracks in his hooves far before the others. He also has really big feet, and always has. Even when we had a farrier who trimmed other POAs feet tiny Moe's hooves have always been larger. He has striped hooves, if it makes a difference. He is 6 years old.
My paint mare, Sadie, has relatively nice hooves. Her front feet stay better usually because she drags her back feet. Her rear hooves actually are square and don't have any toe. It doesn't seem to be a pain issue, because if you lift her head up she picks up her feet. She has never been lame but I am sure it is somewhat of a problem balance-wise when her feet only grow out and not forward. She is 14 years old and she has black hooves except one of the back ones that has a white patch on the side. She also likes to walk off the trail and on the gravel threshold between trail and field. It is like she seeks out the rockiest path to walk on.
Gypsy, my 20 year old Morgan mare, has the very nice hooves. When we got her she hadn't had her hooves trimmed for a very long time. But since then her little black hooves have kept quite nice. She isn't ridden too often because my family is full of giants and she is a tiny 14.2 hands and fairly petite. (If she were a stockier horse I would ride her.) And the fact that she goes as fast as she can go all the time. Tight rein = trot, loose rein = gallop.
Then we have Scarlet, a Bashkir Curly who has decent enough hooves. Three hooves are black and one is white. Her hooves are fairly ressiliant, and I have yet to have a problem with them. She is not broke so she does not get that much exposure to hard surfaces. She is really fat, so I have to get rid of that before it becomes a problem.
And thanks guys for the feedback! ^-^ It is one of the subjects I am terrible on as I have never really been taught about it. I will most likely keep them barefoot as that is the easiest thing to do, and they keep pretty well that way. I never really like to ride any faster than a walk on the trail, anyway. I ride my gelding and he is slower paced then the other horses. But I will have to keep that in mind to remind others, and my Moe will have to summon his Pony Express roots to relay the message to those quick horses.
Also, I will look into hoof boots. Especially for Sadie and her 'walk on all the gravel you can possibly find' attitude.