Many bike GPS units also include sensors that monitor your pedal cadence, heart rate and pedal power. However, there are multiple downsides to using your smartphone as your cycling GPS.
As you track this info, you can mark your progress as you seek to improve your fitness. The weight of the device is important to consider, especially if you’re a serious cyclist wanting to reduce weight and improve your aerodynamics.
I actually prefer SD card updates for their simplicity and ease of use.
Of course, map updates usually aren't free, but nearly all of the major GPS device manufacturers are starting to offer devices with free lifetime map updates.
Powered by HERE, each map update includes new and modified roads, points of interest, addresses, signage, and much more.