The update would likely include Di but no update to maps. For better maps, you will need a Navionics or Lakemaster SD card. For S/W updates, I just use old Sandisk 1 or 2G cards. Speed not important for the S/W load, and like to keep seperate from what I use for recording. For recording, use Sandisk Extreme III w/30MBs, in 4G or larger. Have fun with your "new to you" unit.