The fenix 2 is an awesome hiking/fitness/GPS/heart rate monitor watch. By far the best for hiking of the three Garmin fitness GPS watches I've used, if only because of the extended battery life.
I would not think using a watch size GPS for loading maps is very useful. Just not enough screen real estate. Not enough storage. The mapping capabilities are very limited. If you want mapping, get one of the Garmin mapping GPS units. The Oregon and Montana have color touch screen displays and can take Garmin or other downloaded maps. They also will sync to any ANT+ heart rate monitor and record that data along with your GPS track, just like the fenix 2.
For anything but mapping, I'd wear the fenix 2 before carrying the handheld. It covers all the activities: workouts, running, hiking, biking, etc. integrating GPS tracking with heart rate monitoring.