I've got a bike specific unit that also works in the car.... its a Garmin Zumo 660. Yes its expensive, but does everything I want it to do and is bluetoothed to my phone and intercom (Scala G9) for handsfree operation. I cannot fault it in any way plus its completely waterproof and can be operated with gloves on and you never have to worry about taking it off if its raining or hiding it in a tank bag or other carrier. I have it plumbed into the bikes electrical system powered off the ignition and its fitted to a lockable mount covered on my insurance for loss. Its also got a 5 hour battery life so can use it walking, hiking or cycling as well. You pays your money and you takes your choice.
