re:
Certainly someone somewhere must have some fairly definitive data on this. The SS/Edition Watches' sapphire crystal is definitely more scratch resistant than the Sport Watch's Ion-X glass. We don't know how much force would break either type of crystal. Without more info, it's a little difficult to say under what circumstances which would would break first, or crack vs shatter etc.
Many high-end watches use sapphire for the crystal since it's highly scratch resistant and befitting a high-end watch. And I'd hazard a guess that most people how buy high-end kit tend to take better care of it. So smacking a crystal against something, while possible, is less probable.
The Ion-X glass is less brittle and may absorb more energy before cracking/breaking/shattering. How the crystals are designed with regards to thickness and any other spec affect how much energy they can withstand. Another variable would be the surface they're banged against.
If I banged my Watch more than a few times and didn't scratch it, I'd get and replace screen protectors. Some people chose to accept that scratches go with the territory.