Years ago GM Harper held a great seminar in the Fresno area. Dennis Peterson and I brought the RedMan suit and did some drills where Dennis dressed up in the suit and played the attacker role. This was a big get together so there were students from everywhere. Sadly, as we ran through the drill the first 10 guys or so looked like crap and many were black belts. It was obvious they had never trained using full force striking against a padded attacker.
We had the same experience the first time anyone tried this on the Predator Armour we have for our gym, sir.
People learned quickly that proper striking, breathing and follow-through made a big difference. Forward pressure, as we say.
Some individuals from non-kajukenbo schools were making a lot of excuses for why their fancy techniques didn't work.
One person in particular said that his techniques would work "better" if the opponent wasn't wearing full-contact body armour.
While I agreed with the sentiment, I also asked that since I could drop someone IN the armour, how well did he think our tactics would work against someone who DIDN'T have it?
As we had the discussion I could see cognitive dissonance being replaced by rationalization in his expression and body language.
He asked to try again and fell on his face trying his same stuff while Steve Todd (one of my black belts) merely walked into him while wearing the Armour.
As fast and hard as he
thought he was hitting, he couldn't budge Steve at all. Some might think his stuff looked cool, but it did not work.
A couple of my students told me it made them feel uncomfortable because they felt embarrassed for him.
He was wearing a classical red & white (6th dan) belt.
It was obvious that this person (with around 30 years in the arts?) had never tried pressure testing his stuff.

I like Predator Armour because you can hit MUCH harder than you can against Red Man gear, in my experience.
We throw truly full-contact knees and elbows against the opponent in the Armour. I've seen a tendency for people to still pull the strikes a bit with Red Man & FIST gear.
You almost have to, since Red Man seems to be rated for "accidental" contact.
http://www.cqbkajukenbo.com/dynamic-range-and-impact-with-the-predator-armour-july-3rd-2015/