I don't, I probably should looking at the scars (and currently bruises on my knees). I was the only person on the Ed Oxley skills day last week with no pads on. I've got some Kyle Strait ones but I don't find them all that comfortable so I may save up some pennies to see if I can get some POC or 661 soft D30 jobbies.
I didn't like wearing armour when I ride DH but the only time I seemed to crash was when I wasn't wearing it!
2015 Stanton Ti Switchback
2006 Specialized Demo 8
2013 Specialized Allez Sport
1999 Santa Cruz Chameleon
1994 Cannnondale Beast of the East (rebuild still in progress)