Bests & Worsts Reviews from Amazon

This is a definite improvement over the 301. I had several complaints with the 301: (1) The heart rate monitor did not track well, and would often jump up to 240, which was a problem when looking at average heart rate later; (2) The tracking was bad sometimes in the woods, where I run (it could vary half a mile on a four-mile course, and even worse, the elevation could spike 1,200 feet at times and completely change the profile of the run); (3) The unit was not ergonomic, the buttons were difficult to push, and the screen was hard to see; and (4) It took forever to acquire the satellites. The heart rate monitor comes with a new sensor that is more flexible, comfortable, and offers more reliable data. The tracking is much better and more consistent. The unit is much more like a watch, the display is great, and the buttons are much easier to push while on the go. However, it still takes a while to acquire the satellite signal. It is a bit improved, and is not dissimilar from other Garmin products, so I'd have to say that it's OK. The BIGGEST improvement is that this model is more like a typical GPS in that it offers many different modes and screens to track various types of information (one can toggle between three different screens). For example, on one screen, I have the current time, sunrise, sunset, and running time. On another screen I have the grade, altitude, average pace, and current pace. On yet another screen I have heart rate, calories, distance traveled, and heading. It is totally cool. I use this thing for running, biking, rollerblading, mountaineering, skiing, and just about everything else outside. I am really happy that I spent the money for the upgraded version.