As you prolly know, I'm not a fan of groomer burning. I've tended to emphasize the morals of hitting someone else at speed, but yeah, as your post notes, we can be the ones who pay up front.
That said, I own a POC back protector, but it's for backside, steep chutes and such with serious exposure to rocks. As far as I know it's primarily for penetration and crushing protection, doesn't much help risk of broken necks, pneumothorax, cerebral artery dissection and so on. Rarely use it, never when racing. (Note that alpine racing suits do not have any hard armor, just some padding here and there to reduce bruising.) So I try to go like stink on a course, but don't wear any armor.
Likewise, FIS helmets have not been shown to substantially reduce risk of concussion, yours or anyone else's; again, they're still all about preventing penetration and nice right angle blows from hard objects like steel balls dropping out of the skies. The new specs increase frontal padding for gate impacts. MIPS design may well turn out to actually bring something new to the table, but insufficient data so far. Anyway most FIS approved designs are not MIPS right now. So most of us wear glorified bicycle helmets and feel cosy safe. Uh huh.
Having rode motorcycles for about 35 years, actually think body armor for shoulders is not a bad idea; our clavicles tend to say so long to our acromions pretty easily. But the analogy doesn't hold much beyond that.
Personally, I have three approaches to preventing personal injury in late middle age, none of which involve armor: 1) Make sure my body is ready, which means, besides the usual garbage, lots of unpleasant off-season exercises for small muscles that support things like our skull and spine and pelvis (for instance, think about what a boxer's neck looks like, and how that allows him to absorb cranial impacts that literally would kill you or I with one blow), 2) Take lots of lessons from an L3 early in the season when I'm overconfident and rusty, and 3) Dial it back at the slightest indication of either the slope's condition, my attention, or my skill set being less than I expected. An off day can get real bad in a hurry; broke my thumb and nose first week last December simply because I was distracted when I skied through a snow gun's blower, lost an edge on the ice I couldn't see for an instant, recovery wasn't up to mid-season form.
Edited by beyond - 10/10/16 at 10:22pm