Placto offers a extremely fast content engine and forces the browser to use caching if the browser's revision is the same as the server's. I currently use it for all my websites and it saves me a ton of bandwidth and downloading time.
Testing it went alright. It went somewhat slow for a cloud computing OS. It lacks the freedom to at least control and review your hardware. That worries me about external hardware support like cameras, printers and scanners. I had trouble accessing the first screen that appears, but that should be fixed. Certainly needs work before release.