Yes. I'd have to agree. The old MTR was better. It did chunk a little more in the rocks though. As for sidewall failure that's a crap shoot. When it's your time it's your time. The only sidewall I ever blew was on the old MTR but that was in a blizzard at 10k ft. During hunting season. The jeep fell into a deep rut and caught a sharp rock and the sidewall was sliced with ease. Kind of like your sidewall failure with the tree stump on the Coopers ( a really good tire imo). Those types of blowouts are hit and miss affairs.
I'd have to disagree with the sidewall failure. The Cooper failure I had was caused by a tree lancing a tire at full street pressure - kinda like a needle to a ballon and that caused it to rupture. The MTR failures I've seen including during the Nitto testing were all on aired down tires. Rather than pushing past a sharp rock, I have seen the sidewall catch on it and get pulled until it tore. I have seen this multiple times on the trail and it was one of the tests that we specifically did with Nitto while they were developing their K-spec 40. Granted, this has just been what I have seen.