I can tell you horror stories from having the shipping boots on. (from the POV of a vet tech)
No matter what there is - there are two sides to the story. We've hauled successfully for many years without shipping boots. If we have to haul a distance, we may use SMB's or quilts with polos. Less expensive and more versatile that shipping boots.
So there is always pro's and con's to both. In my years of experience I prefer boots. Working with stables importing horses from Europe and doing cross country trips we always used boots. The thicker ones that are really stiff like the OP's are great because they wont slide down as easily.