the product be quite adequate and function well . do not believe they suggestion to buy a 256mb sd card however , unless you be satisfy with 2 or 3 state coverage . I get the 1.0 gb sd card and it give I detail access to over 2\/3 of the lower 48 state . I find a quirk while be instruct to enter a south bind highway from the east . it instruct I to go over the highway and make a `` hard leave '' -lrb- a illegal turn -rrb- , rather than make the right onto the cloverleaf entrance . be careful . -- the internal antenna work quite well but the placement , in my vehicle , require the use of a external antenna . DO NOT buy the Magellan External Antenna . when the weather get even slightly warm , the antenna set off a continue false alarm on my Cobra Radar Detector . Technical support have be absolutely useless . after 6 try , I have give up and buy a gilsson antenna that work much better , have no problem and cost less . Magellan -lrb- Thales Navigation -rrb- either do not understand english or choose to deliberately misunderstand the problem . they will also not offer any refund on they antenna with the design problem . -- in general , I be quite satisfied with the RoadMate 300 , but do not expect any intelligent Technical support .