For ease of use, for being oriented toward the RV user - the Rand-McNally is a great unit. I loved it.
As far as routing - all GPS makers use one or two sources for their road data, and near the same set of algorithms to identify routes. All will give you great directions some times, and some places. All will give your crazy routings and directions other times and places.
Both my older Garmin and my new Rand-McNally Good Sam GPS like to route me to the closed back gates of Texas state parks.
I've had Garmin GPS units for over 10 years. Whenever I had issues - I found Garmin Tech Support great. I had to send in one unit over the years - and a new one was shipped out to me the same day.
Rand-McNally Tech Support has been unsatisfactory in my experience. Continually they tell folks "a soon to released software update will fix that"
I had issues on a trip and started working with them.
Wish I hadn't. I should have just taken the problematic GPS back to Camping World and got another one.
While on the trip, Rand issued an RMA. I sent the unit in. I'm still waiting for a replacement because it was not repairable. I sent the unit in on August 18.
Neither Camping World or Good Sam Action Line have responded to my requests for help getting Rand off the pot.
Next stop is small claims court tomorrow.