I have a question regarding SPI communications. I feel like I have a good understanding fundamentally of how SPI works. However, I'm often confused when implementing the slave select line of SPI.

Is the slave select line on a microcontroller, in general, enhanced via hardware? That is, is there anything different between a slave select output and an output controlling an LED? Do microcontrollers allow certain I/O to be toggled faster when used for SPI?