I've been wearing Draggin' Jeans for years, now and like them. The are a bit warmer than standard denim, but I figure that's a small price to pay for the extra protection. Mine have held up well after much wear and many washings. Me, I'd also look at the gusseted stuff--anything with the kevlar lining. It should be remembered that these are intended to protect against abrasion, not impact, but hey, I'll take what I can get.
I saw an article about draggin jeans in a magazine a few years ago. The company advertisements show a guy sitting on pavement holdong a water-ski tow rope that's tied to a pickup truck, implying that the jeans will keep you protected while sliding along the pavement. So the magazine set up a test and asked for volunteers among the staff to slide along the tarmac behind a pickup. After a period of nervous silence, a "volunteer" was selected and the test began. I don't remember how fast they went, but the testers were amazed. The denim wore completely through in about ten to twelve feet (as a long-time standard Levi's while riding person, I was amazed and alarmed at this), but the kevlar stayed and stayed. The tester reported that he could feel some warmth from friction on his bottom but nothing but some road grime came through the kevlar. They dragged the guy for longer than would ever occur outside of a truly bizarre circumstance and the kevlar never wore out.
Let's hope nobody we know ever actually puts them to a "real world" test, but I'm going to keep wearing mine. Good stuff.