This o-synce (“Oh science!”) unit may be pricey but it offers extensive downloadable GPS data. Tons of functions are available through its tunable multi-cell display, especially if you upgrade it with ANT+ cadence and/or HR sensors.
The numbers are small so the backlight helps on drab days. The fixed mount straddles your stem clamp for excellent positioning. While the side buttons are a bit clunky, our sample came with an optional Bluetooth remote switch that sits next to your grip. The navi2coach uploads to the TrainingLab site for post-ride autopsy via USB and you can download GPX routes for the direction arrow function. The removable battery means you can carry a spare on epic trips too. GPS pick-up can be slow though.