I'm not sure if it's useful (and it's only a guess) but I think there are two mechanisms at work here:<p>1. Minor technical problems at Amazon affecting [at least] a few vocal customers<p>2. Rackspace running a PR campaign in favor to their newly launched cloud product<p>I'm not sure to what degree these two are connected but the timing seems a bit suspicious, with a bunch of pseudo-benchmarks (paid by rackspace) cropping up almost at the same time as these reports about EC2 problems.<p>As a matter of fact there has always been some variance in EC2 instance performance, as anyone who has run more than a few nodes can confirm. It's the nature of the beast.<p>None of the reports I have seen provided convincing data for serious large-scale problems. A peek on a few hundred instances simply doesn't cut it when amazon is said to be running around a million of them. To add a datapoint of my own; we are running almost a hundred 24/7 instances here for batch media processing and I can't see a difference in performance between now and November'09.<p>And even if the reports are true I'm not exactly worried. Amazon is the first and largest cloud operator, so it's just natural that they hit scaling barriers before others do. If there are problems they will fix them and move on.<p>Ofcourse all this sounds much more exciting when you wrap it up under a sensational headline, along with a few meaningless but colorful graphs...