What are the Maps Like? Maps of course of an extremely important feature of any GPS device. Each receiver will come with different types of maps. It would be wise to decide beforehand what type of maps you will need the most as well as how detailed you would need them to be. A typical handheld GPS will come with a certain amount of maps already stored within and some will have the capability of adding more maps if you need them.
Enough Storage: Check to see if the model has enough storage space to be able to upload specific maps that you may need down the road. This is not such a big issue this days because most GPS devices can with a slot for inserting an external memory card.
Is it Waterproof? A waterproof unit is far more versatile and can be used in the rain, while riding a motorcycle, or even while boating or kayaking. If you choose a waterproof unit then look for a waterproof rating of IPX7. This means that it can withstand accidental dunks, rain as well as splashes from water. It can also float.
Deciding Which One to Buy? After considering all of the important features above do a little research and watch out for units that offer a lot of unique features that not only drive the cost up but also may never get used