So I am sitting in the audience watching another ESRI Demo on how the 9.3.1 AGS technology is so much faster than the 9.2. A couple of thoughts hit me right away. First, well that is a pretty low bar to get over; we all have heard the complaints from our clients. Second, of course they have the super duper Inline Server sitting 10 feet away from John Calkins running a demo that is optimized to show off performance improvement. It made me wonder, well how big of a difference does Caching make, and for the vast majority of our client applications who require dynamic data, how well do the MSDs really improve performance on real map files.