Surely it depends on what was running, here may be tidyup processing that doesnt gate on disk speed, for instance if you are mid TM backup it will need to stop that backup before shutting down. Aperture will need to close its library etc. My boot drive is an SSD, data on HDD so possibly more HDD-esque in that regard.Since OP has a SSD, than yes its long. My SSD gets me about 3 seconds to shut down. Have you done a PRAM yet ? Of course I have Yosemite not Mavericks. Mavericks on a Hdd is about 20 seconds for a shut down.