It offers full AHCI support for hot swapping SATA drives on any of the SATA ports that connect to the mobo so yes, it is important to have. You don't even have to "safely remove" any drive you plug in, just connect and disconnect whenever.
I use it to dock my backup drives to the Corsair 650D's top SATA docking bay and run weekly backups. An invaluable software/hardware combo to have.