Routes can/do include audible prompts and zooms but we don't use routes anymore but rather tracks. For our big annual trip I get gpx files (as well as pdf maps) that I upload to ridewithgps and write directly into the device. The problem with routes is that the devices (all Garmins) recalculate routes for themselves based on the waypoints. And it almost never matches our paper maps perfectly. Tracks, however, will match perfectly once defined. For a couple of years I did both tracks and routes just to get the beeps and zooms but it was a little confusing watching for the differences between routes and tracks.
Okay, I think I follow you. So you upload a track file which which creates a more accurate map.
Can I assume then that the track file doesn't include turn by turn prompts? If so you have to be watching the screen constantly to get your turns or am I wrong about that? Personally I've used GPX route files and have no problem 90% of the time. ( Garmin 705 and Android with "Cue Sheet" app )
I think the thing I like about audible prompts is that I can turn the screen off and just turn it back on when I hear a prompt. Saves battery power. ( as long as you don't miss a prompt you're fine. ) Works well when on regular roads but if on bike paths you have to pay more attention to the screen so you don't go off course. No tracking system is perfect but not having to stop to look at maps all the time is just great.