What's the big difference to you? Do you run a 1/8" because of the 1500+ watts you put on your FG? Or do you run a 3/32" because of the weight savings? Oh I forgot, Sheldon told you your answer.

Dura-Ace made a Track Crankset that could be purchased with 3/32" Track-specific (144 BCD) rings. Not sure if the 151 BCD was 1/8" or not.

Back to the topic at hand, how much quieter would the 'road' chain actually give? I'm not sure since they both run straight anyways. If your chain line was off, then the 'road' would probably be significantly quieter. The only major gain would probably be weight, which you would have a significant gain over 1/8" chains. If we couldn't use a chain such as the KMC-SL 9-speed, and had to use an 8-speed road instead, the 8-speed KMC weighs 315g (QBP). Other brands, such as SRAM and Wippermann are +/- 20g within the KMC weight. I can't find a weight for the 1/8" SL chain.