The case for armour

Part of the connection is a paywall protected series of skills classes, and part of it is an invitation-only Facebook page. There are loads of adults, around the World, who have joined up with Ryan to learn MTB activities (Ryan's lessons are activity based in opposition to the PMBI skill based approach).
Lots of these people fall down in pursuit of the new stunt. Lately there have been several discussions about wearing armour.
Meanwhile, I notice that many downhillers on the World Cup circuit are again wearing armour. Sam Hill forgot his once and made it popular to not wear it - and suddenly no one cool wore it. Except in France, where it is a law.
Loads of competitive men and women have the telltale hunch of someone wearing back protection. Fewer have something on their shoulders.

So, should you wear it?

If you saw the last round of the World Cup - in Austria (Leogang) - you might have seen Remy Thirion get the final jump wrong and get tossed into the ground; hard. He broke a lot of bones.
Armour isn't likely to help with collarbones or arms, for example, but can prevent you from snapping off the processes on your vertebrae (the bumps you can feel if you run a hand down someone's back) and can reduce the severity of bruising.
Basically, the slower your impact speed, the more likely armour is going to help. A friend of mine got his foot stuck in his clipless pedal and broke his elbow when he tipped over - ouch! Elbow pads would have prevented that by spreading the impact (and dissipating the energy).
At 80 kmh, armour is unlikely to make a big impact (pun intended) on your outcome from a crash.

Thus, if you are learning to wheelie or bunny-hop and think you might tip over, padding is good. It is why I choose to learn (and usually teach) these things on soft grass - the padding is provided by the environment.
If I was going to race DH I would definitely think about wearing my neck brace again (I ceased because I thought it more likely to cause an accident than save me from one) and my turtle-shell back pad.