this be my fifth gp unit . my first GPS unit be a Lowrance gm100 follow by a Garmin and a Magellan Sportrak and then a Lowrance go2 . all have be good unit . I be very inpress when I first receive the Lowrance h20 unit . I be impress by the screen size first and foremost . second , I be pleasantly suprised to find the car power adapter . shortly after purchase the unit , I buy the software package . it include the map software , a 64mb sd card and the card reader . I be very happy with the set , but I would have prefer a direct cable connection to the unit as oppose to have to use the card reader to transfer datum . the software be also somewhat limit in feature as well . I would like to see more feature involve trail . the map be great and very accurate . transfer datum work great but be somewhat difficult in that you must remove the card which require removal of the battery . I would give the unit five star if it be not for the above limitation . if you just look at the unit itself base on accuracy and useability , it definitely rank five star .