All these stats talk about possible peaks. The valleys are what you need to look at when it comes to cloud performance. It is not about how fast it can go as much as how slow it might be. 1000 IOPS is great but if it occasionally drops to 15 that's a problem. Amazon is slower but more consistent, and that is something that you can plan around. I look forward to benchmarking these Rackspace offerings on my own to see how they compare.