Bolt on cogs

from my experience with downhill bikes and the forces put through discs the strength is no way a issue, i was running 200mm rotors at one point and had no problems at all and other times running a few bolts less and again still had no problems. if i had a disc mount cog set up i would bet my life that it would never break.

I'd agree with this - and add that I'd imagine the chain would break long before the sproket bolts go. The end result would obviously be the same, no brake or drive and not great, but just saying that those bolt on cogs look bomber.