I fully advocate the description of build steps for environments, just as PFCTs encourage. However, the use of PFCTs to prepare and manage environments seems .. suboptimal, in terms of potential for issues. I suppose a PFCT could be useful as a means to automate the generation of environments, but ... IMHO ... it should not be used for the live instantiation/configuration of real infrastructure (which should be more atomic, from some versioned/known quantity). A subtle difference, but important.