2 pairs of obsidian pants here. Guess they are 4-5 years old now. No crotch blow out, but I'll admit my junk is small and probably doesn't put the pressure on the seams that everyone else does.
To me the material in the obsidian pants are purpose built, I'm sure lots of guys have durability issues with it. It's a lightweight, quick drying material, that doesn't stink after 3-4 days. I don't hardly wear them in the east, I don't wear them in briars, thorns, heavy brush, etc. I don't wear my puffy's in that stuff either, at least not without a heavy shell. The corrugate pants are way more durable, I think they are slightly better than my Eddie Bauer Costco pants, but due to the 10x cost factor the EB's are a way better pants unless you need camo.
You just aren't going to have a bunch of durability with lightweight wool. I will say my first lite underwear has way out lasted my other wool boxers. Meriwool? Can't remember, but 6 pairs of those and most look like Swiss cheese, and I didn't think my farts were that caustic.