I recently got the nuvi 500 and a the Topo US24K map on SD. I returned the map (unopened) and exchanged it for the TOPO Southwest 24K DVD. It covers 4 states instead of 2. I installed the entire state of Utah in the nuvi's internal memory. The main reason I wanted the DVD was so I could use the maps on the PC. The maps are supposed to be same on both media. It works great on my nuvi 500. Of course the 500 was designed to work with topo maps. If you haven't gotten the GPS, I'd take a look at the 500. It has a smaller screen than some of the other ones, but it's the perfect jeepin GPS for me. Well almost perfect. BTW, it's the only nuvi that will record a track log as far as I know.