The touch-sensitive bezel is a double-edged sword and much different than previous Forerunner models. You run your fingers on the bezel in a circular motion and touch it or hold it to program the features. On the one hand, it minimizes the amount of buttons on the watch which streamlines the functionality a bit making it easier to program. The drawback, however, is that since it’s touch-sensitive, your data and settings can be altered and even worse, your current run/race information can be totally wiped out if someone or something brushes up against it.
The calculations of current speed, average pace, and of course the distance you've travelled are all extremely accurate with the 405CX. By comparison, however, the feature-laden 405CX is definitely more costly than the older and more trimmed down Garmin Forerunner 305. The lithium battery holds a charge for between six and eight hours which is a little annoying when you’re training many hours a week. For those of you who like training with fellow fitness enthusiasts, the Garmin Forerunner 405CX can share information with other Forerunner 405 users, so you might want to talk your training partners into buying one too.
What sets the 405CX apart is the improved heart rate monitor and its ability to more accurately calculate calories burned. The heart rate monitor itself is wireless and flexible which is so much more convenient. More scientifically sound algorithms were included to account for things like more strenuous exertions, such as elevation gain, while calculating how many calories you're burning in relationship to your heart rate, speed, distance, and other relevant factors. It would be a good idea to compare it with the newer, pricier, and more feature-laden Garmin Forerunner 410.