Patrick,
You may find this interesting:
http://www.gotdotnet.com/team/compare/ Benchmarking Microsoft .NET vs. Sun J2EE: A Comparison of Performance and Scalability
See for yourself how the .NET Pet Shop performs and scales vs. the J2EE Java Pet Store. We took the Oracle 9i Application Performance Challenge, and show how the .NET Pet Shop offers 28 times faster performance than Oracle's highly optimized J2EE version of the Java Pet Store running on the same hardware configuration, based on Oracle's own published data!
Implementing Sun's Java Pet Store Blueprint J2EE Application using Microsoft.NET
Read how we implemented the complete Java Pet Store, Sun's primary J2EE reference application using Microsoft .NET and C#. The .NET Pet Shop implements the same functionality as the Java Pet Store, but does so in 1/4 the amount of code! This whitepaper contains direct comparisons of the .NET and J2EE implementations, including full source code to the .NET Pet Shop, a new blueprint application for the .NET platform. We also used .NET to extend the application beyond Sun's implementation with an XML Web Service and support for mobile devices.
Rich