I have been eyeballing the Garmin Drive smart GPS units. They would require a case , which there are readily available cases with visors and can be permanently mounted.

The Zumo 590 is feature packed, but so is the price tag. I don't need features like the Sirus /XM as I have a tuner already built in with my aftermarket audio system and also have bluetooth from my phone for audio and USB etc... The Drive Smart series has Bluetooth and the ability to answer my phone etc... As I understand it,I can pre plan routes as well with the Drive Smart. I can be equipped for under $200.

My question really is more geared towards whether the other features like the "curvy" road feature and any other features really made it worth while.
My phone has worked fairly well, but it does need a signal to originate a map when searching. This can sometimes be limiting when in remote places looking for directions.