I just came across this excellent material on Technet – the Biztalk Server Performance Optimization Guide. Whats even cooler about this paper is that it goes into some pretty good depth on how to use BizUnit in conjunction with LoadGen to do performance testing. This is really good stuff. I was just thinking how good it would be to see a step by step guide to setting up performance testing, including how to get your solution fully isolated and ready etc and along comes this beauty. Its got a complete configuration file which we can customize and use for our projects.
It gets even better wherein there is an entire section on how BizUnit can be used with the end to end BPM scenario. This is an absolute gem. I remember talking with Gar when we first setup BizUnitExtensions on how good it would be to get hold of the end to end scenarios and setup BizUnit for them and this article provides a lot of that. This, IMO, is probably one of the most valuable articles around not only for BizUnit but also because it describes an approach to testing a complete solution.
Check out the articles and happy Biztalking and testing 
Enjoy.
