I have the same unit and the thing works great. I have the freedom map, and boy is that ever detailed. It even shows 4x4 trails out in the middle of nowhere. I was quite supprised when I saw that on there. I marked a waypoint and it took me right to the spot within 6 inches. I use it only in advanced mode, you will find you have a lot more options in that mode and when you start using it that way, you will never go back to the simple mode.
Hope this helps,