Cobbler, Koan, Juju and Orchestra

Hi, So: Cobbler, Koan, Juju and Orchestra I wondered if anyone here is using any of these, and if so, what's your opinion? Do they work as well as advertised? Are they any good when running with local virtual machines rather than on an EC2-compatible cloud? The ideas look good, but it's surprisingly hard to come up with documentation showing how to go from an Ubuntu install to actually having the whole lot working. (The things I did find gloss over important steps, or only get one part going, such as PXE boot, but not juju.. or juju or koan to boot a machine, but not configure it..) Cheers, Toby