Here's a random assortment of chain observations:
Many BMX riders run cheap road chains.
The chain line on track bikes is actually pretty important if you want to use a quietly running track chain. This is even more important on a 3/32. Being off by 1 or 2 mm can generate extra noise. NJS frames are built to exact standards and should have a perfect chainline. I'm kind of starting to think that the chainline accuracy on many of the modern carbon bikes is just all over the place.
Road chains aren't necessarily smoother running than track chains: the Huub guys tested both and eventually settled on a standard track chain.
Part of the attraction of 3/32 (and even thinner road chains) is actually the aerodynamics at the chain ring. Too me, it seems like we're talking about miniscule marginal gains but that's part of the discussion amongst the World Cup teams. The idea of going big on the front and the rear for efficiency might actually be outweighed, at some point, by the aerodynamic losses of the front chain ring. One of the discussed advantages of the Kappstein is the good aerodynamic transition between the 3/32 chain and the chain ring.