I really wish he would have added GZip as a feature. It's a pretty big problem that Rackspace doesn't currently support it and it makes the speed / response time far less meaningful if other providers happen to (well, for certain uses anyway).
I didn't like that the charts at the start have different scale for the last one and as was pointed out there is geographic variety in response time test which is kind of important. Despite that, it's a good place to start any kind of CDN comparison.
It's too bad they didn't cover SoftLayer's deal with Internap. Not quite in Akamai's league, especially outside of the US and Western Europe, but far better than some of the smaller CDN upstarts. Pay-as-you-go pricing, large network, and reasonable flexibility via web and API tools. We use them at Wikispaces for international static object delivery and have been happy with the service.
The maximum expires header you can set with Rackspace's Limelight offering is 3 days. Fine for software delivery, one-off large images and files, etc., but not suitable for static object delivery. If I were a cynical man, I'd say this either drives up Rackspace's revenues or pushes larger customers up to CDN contracts directly from Limelight.
It's a shame, because Limelight has a strong offering. I would have spent hundreds of dollars a month on that service if the headers were truly configurable.
