I use an RV version of Garmin. Many disparage the software, but not the hardware due to a definite learning curve, but I have found it useful.
Pros:
* You put in the dimensions of your RV and it tries to keep you on routes suitable to your rig. It is especially helpful on low clearance overpasses. It seems to have up to date information and has saved me on at least two occasions (meaning warn me when I was approaching, having departed from the planned route it laid out for me to begin with).
* It includes (or you download) a route planner (BaseCamp) where you can lay out your entire trip itinerary with fuel stops and overnight stops including travel times, etc on your computer. Then you can transfer it to the GPS device. This is one element where the "learning curve" complaint comes into play. Many prefer a simpler process.
* You can add points of interest (POI's) including fuel stops, rest stops, stores and RV parks to the BaseCamp data for planning. A lot of information is available on line to give a more comprehensive list than is available in BaseCamp itself (or all the other planning tools mentioned so far). Again, this capability adds to the learning curve.
Cons:
* It sometimes routes you around things that are probably OK, for perhaps dubious reasons. For example, it doesn't seem to like traffic circles ("roundabouts"), some of which, having seen them, I felt were navigable in my rig.
* The aforementioned learning curve. It helps to be somewhat familiar with computers, syncing devices to computers (like you would your phone, tablet or MP3 player) as well as downloading computer files. Google Earth for viewing stops and destinations with the satellite view is also very handy.
My two cents.