I have been using my Garmin Edge 705 for awhile now but it doesn't show alot of the roads that I ride.. So I need to get some decent mapping software for the Unit and am not sure what to get.. I also have a Garmin 60CSX that I would like to be able to update the software on also.. I originally thought I could just buy an SD card with some maps on it and take it from Unit to Unit but then I was told that you cannot update the SD cards. Then I hears someone say that you can just download the program to a blank SD card and then you can get free updates... What is the best way to do this? And what's the best software.. Looking for Roads, not Topo or anything like that..