The Garmin Edge 840 is a compact GPS cycling computer designed to provide comprehensive data and navigation for cyclists. It aims to strike a balance between touchscreen convenience and button control, while also offering adaptive coaching features. Overall, it's a well-rounded device with a lot to offer.

Pros
• The combination of touchscreen and physical buttons provides flexible control, especially useful in varying weather conditions when gloves are needed.
• Targeted adaptive coaching gives riders personalized workout suggestions based on their fitness level and upcoming events.
• Advanced navigation features, including preloaded maps and turn-by-turn directions, make it easy to explore new routes.
• The unit's compact size makes it easy to mount on a variety of bikes without being obtrusive.

Cons
• The touchscreen can sometimes be less responsive than desired, especially in wet conditions or with gloves.
• The sheer number of features can be overwhelming for new users, requiring a significant learning curve.

Verdict
The Garmin Edge 840 is a solid choice for cyclists looking for a feature-rich GPS computer with advanced training and navigation capabilities. While the touchscreen isn't perfect and the abundance of features might be daunting to some, the overall performance and adaptability make it a worthwhile investment for serious riders.