I don't have any objective testing results, but an argument could be made for either being stronger: Eg., the shorter pin length on the 3/32" chain induces less stress on the side plate, therefore rendering it a stronger chain. On the flip side, a 1/8" chain with its heavier-bigger plates and pins just by sheer materials alone, render it a stronger chain. But now let's throw a monkey wrench into the equation and go with the mass to diameter ratio and which one ends up the strongest???? I have no idea. I have never snapped a chain either 1/8 or 3/32 that was due to chain failure and not my own error.

That all being said, I don't think the focus should be so much on the chain, neither size: 3/32 vs 1/8, nor type: bushing vs bushing-less; as opposed to the other components of the drivetrain. As has been said, the best/roundest/most precise rings are almost exclusively 1/8". If you want to run your chain tension high, you better be as close to perfectly round as possible, and at least it seems to me that 1/8" is the way to go there. When considering rings, as opposed to chains, size does matter. Given similar engineering and materials, a 1/8" ring will be stronger and hold its shape against deformation under load better than a 3/32" ring, I don't think there could be any argument there.

zac