IMO barefoot is the best unless you don't have the time and have a horse that has hooves that will not allow for a healthy transition.
I have a 9yo QH that gets ALOT of exorcise and he doesn't have shoes...his feet are hard as rocks...
BUT it took a long time for them to build up and recover from having shoes on him...the shoes (with my horse) had a tendency to restrict blood flow throughout the hoof...they made his hoof walls very brittle and weak b/c of the nails...and there was obviously no natural wear from being active which enables me to see how balanced we are and how much progress we've made...
Since I took his shoes off (late 2005)...he has been a different horse...I live in S.Florida and I have a natural trimmer come to me...his work is amazing and the knowledge is just incredible...
Anyway, sorry to ramble...if you want more info on it or on my specific case, I would love to share:)
Kristy
Oh, my natural trimmer costs me just as much as my farrier used to...it is not at all less expensive (unless there were corrective shoes involved:)