I've been shipping my blue book tiles at least since 2003 (did I ship any of the botanicals in 2001? I don't recall), so: hundreds, safely. The only damage or loss incurred was one tiny, easily repairable edge nick. This summer, however, the USPS finally lost one on its way to a client in Brooklyn. Fortunately, it was insured and so when I, after hours on the phone and online, determined the tile was truly lost and not just slow to arrive, I went back into the studio and painted a second. This one, to the client's relief and to my relief, actually made it all the way.
I can argue in either direction as to which I prefer.