YES definatly worth it... depending on your situation though:
SSD = Solid State Drive
SSD is much faster because it has no discs and does not need to spin.
Sata = Serial ATA
Sata has discs and is measured in speed by the RPMs it spins said discs.
SSD wont be destroyed by vibration and shock like a SATA drive would because of the lack of actual discs.
to some it's a matter of need it ... and to some it's a matter of gotta have it.