Thats funny. My surly cog (also the new style) was by far the noisiest cog I have ever tried, but there are a lot of other variables that determine DT noise, including chain, chainline, type and amount of lube, state of wear of the DT, vibration resonating properties of the frame, fork and wheels, etc.

By comparison, the differences in tooth shape between different brand cogs (when new) are minute, and, I am willing to bet, are not a major contributor to variation in drive train noise.