The Mobius are game changers. The mobility is 2nd to none and I tried a couple of the other expensive ones. You literally can run in them. They aren't cheap but out of all the people I have talked into them, no one has been disappointed. Anyone who doesn't wear knee pads has knees of stone or just doesn't ride very hard. I would bet a ton on the later ?
Knee pads are great.
It's the improperly setup braces that can transfer excessive motion into your other joints.
Braces can have pads, pads are not braces. I've seen quite a few braces that have nothing for impact protection though.
No matter what, a tree branch or rock can find any gap in the pads and put a damper on your day.