garmin is the main one, with the tread. otherwise a gps capable tablet with a good case is a nice option as well. I run a samsung tab a 8" version on my dash using a marqcad eng holder on my xt and in my my x3 which has been invaluable for opening up horizons on trails. I dont have a 100% waterproof case but i havent had any trouble with it yet, even in some rainy situations. I tape off the camera holes and such to help seal it just in case.
VVmapping along with some others have maps that can work on both, depending on location of riding. i use vvmapping on both garmin and my tablet. the nuvi i use is on my snowmobile, unless i want to route. then i would use it in the sxs. the only downfall with the tablet is that it doesnt route with vv yet, as it uses orux maps app to display the trails.
steve