Garmin Pros
Garmin handheld GPS units are typically waterproof to an IPX7 rating, meaning they are waterproof for up to 30 minutes at a maximum depth of 1 meter. Garmin offers models with detailed local maps and the ability to add more maps featuring local points of interest. Many of the mapping Garmin handhelds, such as the Oregon and the Dakota, feature paperless geocaching which allows users to connect the GPS to a computer and download geocache coordinates directly to the GPS.
Garmin Cons
Most Garmin handhelds do not float, and though the units are waterproof to an IPX 7 rating, the battery compartment is not. Also, most Garmin models do not have an electronic compass, nor do they have a barometric altimeter. Even with the high end mapping handhelds, only a few models, like the Oregon 300, offer an electronic compass and altimeter. Many of the basic handheld Garmin models only have a serial interface to connect to your computer and download maps. This means that uploading maps can take a long time.
Magellan Pros
Like the Garmin, most Magellan handhelds have an IPX7 waterproof rating. However, the battery compartment is also waterproof which means that they float. This is helpful if you accidentally drop your handheld while out on the water. While most Garmin models have the tracklog feature, the ability to backtrack a tracklog seems to be more common on a Magellan handheld, allowing hikers to easily return to their starting point. Most models of Magellan come with the electronic compass feature and the barometric altimeter feature. This is great for hikers, as you can tell when a storm is coming in. In addition, Magellan GPS units have lots of extra features, such as digital cameras, flashlights and even voice recorders.
Magellan Cons
Like Garmin, Magellan's Triton series also offers paperless geocaching; however users do not have the ability to mark a cache as found, which can be confusing if you plan to hit several geocaches in an area. The standard maps that come with Magellan aren't as detailed as the local maps found on some Garmin models. This can be a problem if you are trying to drive to a particular trail and you only have basic maps and a compass.
