I've crash tested the Buell Adventure pants - twice.
First time, over the bars and off to hospital with all sorts of damage, 5 months off work. The physio said my kneecaps had the most damage he had seen without breaking. Confirmation to me. (Insurance paid for the replacement padding.)
Second time, 100mph slide through asphalt, gravel, grass for football field width. Walk away with small bruise on side of knee (bruised elbow, broken rib but you were asking about the pants) and ride home. Confirmation to me. (No witnesses, I'll pay for the replacement padding.)
Summary: they're good, protection is good, good in summer (I ride when naked would still be too hot, parka would still be too cold). They're made by Joe Rocket, but better priced. (Probably their Atomic pants would be the closest.)
Me, I won't ride without something with armour and designed to slide. All the gear, all the time.