I had a Magellan once, what a mistake. The thing ate batteries like crazy, totally useless! Garmin is the only way to go
I have an OLD Magellan 300?? Map. I use it for marking hotspots while ice fishing. It gets me back to within 3 feet consistently. No details on the Lake and only main roads on land. No elevation contours. Only good for retracing routes and finding the waypoints. It does eat batteries for breakfast. Buy them in packs of 20 twice a season. If I was buying a new handheld I'd get the Garmin 68 ST or 72S. Just my 2cents.
I have magellon 300 & 400 - the 400 eats batteries for breakfast. Now it won't connect to the pc -useless. I will never buy another magellon gps. Go with garmin. Less problems. BTW if that was a triton 300, there is software (free) available where you can make your own maps from a jpg and use vantange point to load them to your 300 if you got the cable. If and when I have to buy a new gps, it will be a garmin.