For those of us interested in running latency-sensitive applications on vSphere, Bhavesh Davda, from the CTO's office, has created a comprehensive guide for tuning vSphere for such applications.
Some of the tuning options are very familiar to those working with low-latency applications, e.g., interrupt coalescing settings, and some of them are relatively obscure vSphere specific options. Using a combination of these options, we saw noticeable improvement in performance of some latency-bound benchmarks. As a bonus, the guide provides in-depth reasoning for some options.
You can find more details here and the complete whitepaper here.