Best GPS for RV

I am told that the 465T and the Dezl GPS have ability to put in heights and weights and it will WARN you when you get near the bridge or whatever but do NOT plan the route around the bridge etc. I am waiting until they come out with a GPS that will route only on roads you are allowed on and that the routes do not include low bridges instead routing you on the roads but then warning you it the bridge coming up is too low, that is TOO LATE. Backing up a huge rig either Class A or fifthwheel is not an option sometimes so want it to route around it.