^Yap, you can also update your amp's firmware with it.. I have a Spider IV 75, the firmware version was 1.04, i updated it to 2.0 via FBV MK II and it gave me some extra stompboxes and mods. Not sure about you, but i bought the FBV MK II for around 900 Danish Kroner, around 90-100 euros, but it's worth, totally ^^
Enjoy your Spider 120