[tantalic]

While I quite agree with your general point I think GCD is often under appreciated. Characterizing GCD as "mostly just a thread pool with a nice API" glosses over the key feature which Mike Ash specifically points out is not in this implementation: "the number of threads in the global pool scales up and down with the amount of work to be done and the CPU utilization of the system." Making the pool aware of the utilization of the whole system as a whole is the key feature of GCD. This also cuts to why something like this is best if it is created and promoted by the system vendor: the more GCD is utilized by the system software and third party applications the better the system will perform as a whole.