The only real indication that the drive was on the verge of dying was the periodic drops in RRER below threshold. That may just be a coincidence, but I still think that the Mushkin wasn't really all that far along, and certainly not past some point of no return. It didn't even have 380TB of raw writes on it yet. Perhaps you can only write so fast for so long to the drive before something (bad) happens. The M4 wasn't really all that much slower if you compare incompressible write speed, and with 25nm NAND as well.

I think this is more like a 'panic locked' Indilinx.

I guess I was just expecting a little more as toggle NAND drives are positioned as premium products with premium nand. If the drive had RAISE, maybe it would be a different story, or maybe it would be dead all the same. It just feels incredibly random, and that's not confidence inspiring. I wouldn't have a problem with using a SF drive for a boot drive, but I'm guessing that they are not well suited to surviving endurance testing. If the Force 3 has a similar fate to the Mushkin and the F40-A I think we need more of an explanation. I would consider this just rotten luck and not even related to the endurance testing had the F40-A died in exactly the same manner.