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.
I feel it's slower after the 10.9.5 update?
I just did the PRAM no difference....when I shutdown it goes to the solid grey screen for 7 seconds, the black spinning wheel shows up for about 20 more seconds and then it shutdown.
The app store sandboxing features in Mavericks are what is causing the slow shutdown. Nothing you can do about it (other than get a cup of coffee while it shuts down).
Shutdown in the Yosemite beta is much quicker, so it seems this will be fixed when Yosemite goes live.
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.
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.