Hey, the 500 is an older model so i cant remember all that well but i think its a 256 Card. A 1Gig would cost around £20 online and more like £30-40 in the stores. The 700 has a 1GB drive, and thats holds all of Europe and two of each voice for each language it supports as well as UK Speed Cameras. So i would say a gig is enough. I cant remember though if the Maps of Europe that are pre-loaded on the 1GIG 700 are complete or just major roads.