[header] How to choose a magellan navigation system [title] Think of whether you find yourself using gps infrequently. [step] Use of an available magellan roadmate navigation smart-or i-phone app, in some cases, is the only system you need in that case. [substeps] You receive all of the same features of the roadmate navigation system through the roadmate app, without the need to carry a separate gps unit. 
The problem, however, occurs if your use of the phone frequently interrupts the gps operation. That and other uses may be reason enough to purchase a magellan gps unit.