My cheap Casio G-Shock can handle better than that... The name Ion-X makes it sound fancy, like it's invulnerable and uncrackable. No. But that's just me.
Ion-impregnated glass is not hype. It is a valid material for a scratch-resistant display. One variant, Gorilla Glass, was a great big deal when introduced on iPhones not that long ago, and it remains the screen material for the iPhone today.
Glass has a Mohs hardness between 5 and 6. Some mineral glasses such as fused quartz are a bit over 6. As we know from Consumer Reports' testing, the Sport's "Ion-X" glass has a hardness between 7 and 8. When reading about Mohs hardness, Wikipedia's page is quite good:
http://en.wikipedia.org/wiki/Mohs_scale_of_mineral_hardness
There are plenty of watches out there with mineral-glass crystals, including sports-oriented models like my own beloved Casio Pathfinder. In fact, most mid-to-high-end Casio designs use a mineral glass. It's scratchable but very tough otherwise. They do offer sapphire crystals on some models at their high end. Those are certainly less scratchable, but actually less tough in key respects: mineral glass (including Ion-X) is superior to sapphire against cracking when struck. Sapphire is hardest but brittle!
(Acrylic is another watch-crystal material... I have two cheap Casios with that "crystal". Acrylic scratches like the dickens but can be polished easily, and it's way less brittle than any glass and certainly sapphire.)
One thing that makes all models of the Watch vulnerable is the lovely rounded-edge display that tapers toward the edge. This, rather than the crystal material, strikes me as the most significant difference versus your tough G-Shock. The corners of the Watch are emerging as a vulnerable point where it's easy to fracture the crystal if you knock your wrist against something hard. Most Casios have a raised case bezel; my Pathfinder's crystal is actually inset into the case by a shade under 2mm (I just measured it with a caliper). This certainly helps protect the crystal, and it shields the crystal's vulnerable edges entirely.
So this is a complicated topic that goes well beyond crystal material to include case design. You're comparing a smartwatch featuring a vulnerably-positioned interactive touch display with a sportwatch designed for intensive activities. In a way, it's like comparing the off-roadability of a Tesla with a Jeep. Not quite fair, in a way.
Meanwhile, some brave soul with a scratched Sports might want to try the nostrum documented (with Casios, ironically) at
http://forums.watchuseek.com/f17/how-remove-scratches-mineral-crystal-works-717486.html ...I'll start a thread on that in hopes that someone might report back if it works for them. But, again, the Mohs hardness of the Ion-X glass is higher than that of the Casios' mineral glass, so this trick might not work.
