Theres a consistant, considerable gap between their "raw" benchmarks (things like netty, node, plain php, etc.) and frameworks hosted on those same platforms. I think this is something we should keep in mind when we're tuning performance-sensitive portions of APIs and the like. We may actually need to revisit our framework choice and implement selected portions outside of it (just like ruby developers sometimes write performance-critical pieces of gems in C etc.) or optimize the framework further.
I'd like to crunch these numbers further to get a "framework optimization index" which would be the percentage slowdown or ratio of performance between the host platform and the performance of the framework on top of it. I might do this later if I get a chance.