I have the 7710 and have used it for about a year. Overall I am happy with operation of the unit. The 7 inch screen is the best feature in my opinion. Like every GPS it is only as good as the data base it draws from. It not a very intuitive unit when putting in destinations and at times can be a bit frustrating to get it to take addresses or locations. It also has a habit of trying to send me way out of the way to get to a destination. Also mine came with free updates for life but I cannot get RM to acknowledge any of my emails or get hold of anyone on the phone that can help me. They keep transferring me from person to person with no resolution. I bought it from Camping World and that seems to be the problem with the update situation. Of course Camping World says that it is not their problem and I have to talk to RM. Frustrating to say the least. The 7720 seems to be an improved unit over the 7710.
Do you know what a learning experience is? A learning experience is one of those things that says "You know that thing that you just did? Don't do that."