I have only lost, without a trace, one hoof boot in about 8 years. And that was because we were up the side of a mountain when I realized it was gone and I didn't want to go back and look for it. So, at least for me, it's not like they get lost all the time! I think I have also had one or two come off when either the cables broke or I was using a size too big for the horse, but in those cases the "gaiters" (these were Easyboot Epics) held them on the foot so I never lost them. Maybe me and my horses are lucky, but I have never had loosing a hoof boot to be a real issue. We canter here and there and do LOTS of rocky mountain terrain.
What I do find to be a pain is that occasionally parts break, like the buckles or cables. But I have gotten pretty good at replacing cables with cable from the hardware store. The buckles generally break under warrenty, and I patch worn gaiters myself. Again, I use Easyboot Epics.
I haven't had good luck with Old Macs or Easyboot Bares.
I really, really want to try the Renegades or the Vipers.
I ride all the time, probably 50% of the time bare and 50% of the time in front boots, depending on who I am riding with and where we are going and when the horses were last trimmed.
Which brings me to trimming. I find that if the feet get long enough (like towards the end of the trim cycle) I don't even need to use boots because the feet have enough hoof on them for protection in the rocks. But I pretty much always use boots right after a trim. If I need touch ups to get the hoof small enough to fit in the boot, I just use a rasp. But I also do my own trimming so I can trim whenever I want and don't have to rely on a farrier.
But I have been "doing barefoot" for about 8 years now. I can't imagine ever going back. But I understand shoes are more convenient for some folks. For instance, I have one friend who gets all her horses shod and won't even bother with a boot if she looses a shoe....she just waits for the farrier. But I'm not like that. I would rather be in control of my own horse's feet. And I never have to worry about lost shoes. :)