Someone just posted a link to this benchmarking research done by Middleware Company on the WinTech Offtopic list. Considering Middleware Co. specializes in Java technology training, you'd be skeptical of some skewing in favor of Java, but all the benchmarks clearly show the .NET implementation blowing the doors off the Java implementation. Not only that, but in less lines of code!

What's more remarkable to me are the differences between the 1.0 .NET framework and upcoming 1.1 .NET framework (Everett... still in beta), especially in the SOAP category. It looks like Microsoft's framework teams have done some performance tuning for this upcoming release which is a bonus for any application built using the framework.

In the end this looks like an excellent, unbiased comparison that should prove useful to those that have to justify .NET in any technology debates when it comes to performance.