My first ride with this radar detector and it was extremely useful. It easily mounted to my 2013 speed concept seat post and it easily connected to my Edge 520 bike computer. Out of the few dozen cars that passed me from behind, it warned me about every car. For the Edge 520, when there is a new car approaching, there is a short beep and the outer edges of the screen turns Red. Once the car has passed, the screen goes back to normal. If there are several cars in a row, there's only the 1 beep but the outer edge of the screen remains red until all cars have cleared. I was surprised at how handy this radar is and felt safer with it. I no longer need to constantly turn my head back to check for cars and can concentrate on the road ahead.
The Garmin Power Pack is a great tool to extend the life of your Garmin Edge on long or multi day rides. Two issues to watch out for 1) The battery pack clips into a special Garmin bike mount. It is tricky to get it to click in. On my last ride I thought I had it clicked-in and secured - but clearly not. 20 miles into my ride the external battery pack was no longer with me. 2). When you buy the battery pack, it does NOT come with the special bike mount. Unclear if you can use a standard bike mount (?). The special bike mount costs another $40.