Do I need a cycling computer with maps and navigation?

It depends on your riding. Across the reviewers we read, riders who explore new routes or do long rides strongly favor units with full color maps and turn-by-turn navigation like the Garmin Edge 840, Edge Explore 2, or Wahoo Roam V3. If you mostly ride known roads and just want speed, distance, and training data, a cheaper unit such as the CYCPLUS handles the basics for a fraction of the price.