Everything you need, nothing you don't.

I am very impressed with this little unit. The software and interface have been very well thought out. It's small, light and easy to read. The Forerunner 101 is specifically designed for runners, so lacks comprehensive navigation features, though there is a rudimentary map-plotting feature with the ability to set waypoints and track your progress on various scales. You cannot load map data.

The features for runners are really what this unit is about. It has some really nice touches, you can set pace alarms (both high and low), train with a 'virtual partner', and see your relative positions at a glance, configure a custom page, to display 3 fields of data most relevant to you. Pace, distance, time, altitude, calories burned, to name a few. There are some really nice touches, which I have found most useful. Configurable automatic split times, and a configurable 'auto pause', which stops the timer and pace interpolator if you stop, or go below a certain speed. (Like when you're waiting at the crosswalk). The screen is clear and simple and features a nice orange backlight for running at night.

I'm training for the Chicago Marathon, using the Hal Higdon schedule. Until I got this unit I had trouble charting out all the different distance runs I have to do. Now it is a snap. Knowing your pace is a great help too.