http://www.surlybikes.com/spew3.html

"4. 1/2x1/8" chains vs. 1/2x3/32" chains. 1/2x1/8" chains suck. Run whatever you want, but bigger isn’t better here. Yeah, they’re wider, but according to manufacturer-supplied data, they’re not stronger and they are definitely not of better quality. Multi-speed drivetrains is where the bucks are at, and chains that work on such drivetrains are where the manufacturers of chains showcase their innovations and developments in quality. The rollers are better, the plates are better, the pins are stronger, and the construction method (riveting procedure) is better on all multi-speed 3/32" chains. I guess if you grind your chainring and chain down the handrail every night at the local pub, a bigger 1/2x1/8 " chain will last longer, but most of us don’t and it won’t."