Yahoo have come out with a firefox/firebug extension that does a performance analysis webpages called YSlow. It provides feedback on loading times based on website construction alone, not host or internet speed. I tried it on my custom forum and got a 'A' YSlow rating with 90-97%. Admittedly I had focused on making a high performance forum so it was to be expected. Do you agree with the YSlow ratings for your webpages and do you think its useful for your overall design process?