I use chef for about 10-15 slicehost nodes at work (in production for about 3 months now). It's worked well thus far but requires writing some bootstrap scripts

I use chef for about 10-15 slicehost nodes at work (in production for about 3 months now). It's worked well thus far but requires writing some bootstrap scripts for installing chef on a fresh instance and a fair amount of diving into the DSL (and sparse areas of documentation) depending on your needs. I also developed all my recipes from scratch (didn't use any of the preset opscode stuff, though those are great examples of what can be done and very useful for standard installations of things). I haven't worked with the new recipes mentioned either, but it looks like chef is beginning to grow into some of the potential created by some of the recent infrastructure enhancements. The whole ordeal probably took about two weeks of learning, tuning, and testing, but it could be MUCH quicker for more standard and homogenous server stacks - you can start with recipes used by Engine Yard and 37signals, for example.