I recently went from a "non-mapping" to a "mapping" GPS (Garmin E-Map). It's a little pricey ($299) but I think it's great. You also have to buy Map Source topo software to download trail maps. One trick might be to coordinate with someone else who buys a Garmin mapping GPS and split the cost fo the software ($150) since it looks like there's no limit on multiple downloads, but I'm not sure. Garmin makes a $20 handlebar mount for the E-Map. The E-Map is not as robust as the GPS-12/45,etc. Might be wise to buy a cheap protective case. Maps display in several scales of detail and with the recent removal of signal error, the low scales are very useable. Display gives you a moving map while riding, showing your frequently updated position on a topo map at all times. Only uses 2 AA batteries which seem to last about 12 hours. Overall, it's a neat step up from traditional GPS. You can also "edit" the topo maps with trail designations and your personal waypoints with a variety of symbols. Basically, the mapping GPS eliminates the need to stop and pull maps to navigate towards your destination or figure out where you are.

 

One thing to remember is that Garmin has lots of accessories, which is good. The Magellan doesn't have that many & they are hard to find.

Don't let the salesman talk you into something you don't want.