I have had this unit for about two years. In "RV Mode", it works okay but as with all devices there are caveats.
First, the unit will route you based on the maps you have installed. In some instances, I have been routed over an underpass because the mapping did not know the clearance for that bridge. This is good, I guess, if the underpass was too low. But on an interstate, most of these are high enough to clear a 18 wheeler so it is high enough for my rig and I just allow the unit to "recalculate"
Second, also based on maps installed, is the route the unit will put you on should be compared with other routing applications such as Google Maps and the Good Sam travel planner. I once had a nice route planned but when compared to other apps, I found a railroad bridge that was only 10'6" high and a serious traffic delay due to road work.
Third, be sure to have "outs" for those unforeseen and unknown obstacles to your route. Even Google, Good Sam and Mobile RV do not have anything about traffic accidents. My unit has the traffic monitor installed but I have never seen that work very well. Most times I am in the traffic when it finally tells me that there's a delay for the next 20 miles!
Fourth, make sure your device can add Points Of Interest (POI) with proximity alerts. I have several POIs for RV Parks, Rest Stops, Pilot/Flying J, other Truck Stops, etc. All these add additional functionality and can assist with making travel easier. On my Garmin, you can change the location from where I am at to another location such as where I am going or where I may need gas.
Finally, I believe that there's no perfect solution. Look on You Tube and see what each device has features and will it be what you need for your specific travels.
Good Luck.
But when you ASSume something... 
Linear Mode
