I read all I could about all the different gp . I choose this one becouse of it be portability . it have it be own power source . it be small enough to carry in my pocket . and also the price . I have use it alot . I be never lose if it be with I . I do not look at a map anymore . jusy type in where you want to go . it tell you how far and when you will get there . if you decide to go off the route for any reason it will recalucate and give you the new direction . I love this box . I recomend it for everyone .