I use a Garmin Nuvi in my car but it's older and has to be plugged in at all times because the internal battery is pretty much shot. I looked at and considered a Garmin GPS for my bike but I just can't justify spending the $$$ when I already have a smartphone (android), holder, mount, and an external battery pack, along with multiple free GPS apps including offline mapping.
I need turn by turn audible directions (because I'm just that directionally challenged) and I'm able to load routes in advance to my "Ride With GPS" app or use Google Maps (even offline) if necessary.
Sure I'd love another techie toy because who wouldn't, but I really can't justify purchasing it. I'm never riding off road.