I bought a Magellan 400 Explorist because I used Magellan in the Army. That is the only reason I picked Magellan over Garmin. I will report back after my first geocache to let you know.
I guess the important thing is the sport of geocaching itself, not the equipment. I have seen both Magellan and Garmin making big strides to get us geocachers to buy their respective products. If we as geocachers find one product or company providing less then stellar service to us as a consumer base, then we should get together and complain as a whole with our letters and dollars to get the offending company to shape up.
Other then that, my advice as a Desert Storm veteran is this: Land navigation using a compass and a map is an art and skill that is definetely needed when these electronic devices fail in the field. My platoon sergeant demonstrated this fact in a way that I will never forget. He took a gps device, and a map, and placed them in front of the tires of his HUMVEE. After he ran over the both of them, he picked them up and told us the fancy electronic do-hickey was useless, and the paper map was still in good shape.
Just please be safe.