We've been using the Good Sam GPS for over a month now. Haven't used it yet for an RV trip (not before April of this year), but we did take it with us to Atlanta, GA over Christmas. So far, we're very pleased with it. We've been configuring it for the points of interest (gas stations, restaurants, etc.) we want it to display while we're on the road. We've used the wi-fi feature to connect through my cell phone and get real-time weather reports and forecasts, which is nice. We've also used the campground database to locate the full range of campgrounds in the vicinity of our destinations. We've entered the full length, width, height, and weight dimensions of our rig when it's hooked up, so it will be interesting to see how it routes us on our cross-country RV trips.
The larger 7 inch screen is terrific. We use the windshield suction cup to hold the GPS in place, and let the GPS itself rest in the dashboard tray. This has worked well so far. We especially like the 3D display mode, and how it shows interstate exchanges in 3D, with the correct vehicle lane highlighted, and warnings on upcoming speed limit changes, curves, and turns - which can all be modified to the driver's comfort level.
We haven't yet used the extensive set of RV checklists, which can also be modified. We may do that eventually.
One thing we don't have is real-time traffic reports. That requires purchase of an additional device, which we may do eventually.
We won't compare this GPS to other brands or models, because we haven't used others and therefore don't know enough about them to speak knowledgeably. Other GPS devices may be just as good as this one.
At this time, we give the Good Sam GPS a preliminary (after 1 month of use) 4 1/2 stars out of 5. We'll adjust that, if need be, over time.
Don