I don't use my various GPS'S to get there. I only use them to give me a basic route. While driving I use my eyes for navigation. I never have problems with low bridges, or dead end streets using this method.
If you have to rely totally on your GPS to navigate it means that you're not doing the due diligence required up front before you leave.
I have the 760 and it's great, glad to see they have released the sequel. Google maps (which I use also) is great too, but is only effective if you have a signal, or have previously downloaded an area.