Re: [GreenMachine] Armourgel (soft armour)
I think which is "better" depends on the type of impact you take. Striking an object vs. pounding in a landing vs. screaming in/knee sliding. For example, in longboarding the soft ones are probably pretty bad since you wouldn't want them to get peeled down or out of place from shear/friction after/during impact.
As for BASE I guess it's more of a personal preference. I have used both six-six-one knee+shin guards and the soft/gel type. Any squishy bits between your squishy bits and the rock or pavement is nice

. Whichever ones feel like they fit/stay in place the best and that you'd wear more. I like the six-six-one pads worn on the outside when I'll be landing on pavement and going flat and stable...soft armor for other jumps. If you wear the hard/six-six-one style pads under any clothing, a little knee slide can easily shred it. I had a not-that-bad gravel landing where I went to my knees/slid a little and it ripped through my tracking pants.
For aerials, I always prefer protection that you can wear under your pants so there's no extra entanglement/hesitation risk from bridle or PC interacting with them.
But on the topic of kevlar for penetration resistance, I'd say it depends on what body part you're padding. I think the penetration resistance wouldn't be that useful for knee+shin pads, which most people use. For the torso it might be useful.
If I were making my own soft armor, I would want something over the gel that has low friction and high abrasion resistance.