We have the 305, 405, 310xt and the 705. You can get better battery life if you turn off the GPS which more closely matches the Cateye feature-to-feature. The advantage you get with the 305 head-to-head is more fields and two pages of them, courses and workouts. Throw in the GPS and you get tracking. When you get the other Garmins you get power which imo, is worth the investment. The 500 is lighter and smaller but with less fields. The 310xt is mostly for triathlons but my wife uses it for riding with the quick-release mount. I use the 405 for running and treadmill workouts. The 705 is my main bike computer, battery life is awesome and the memory card gives plenty of storage. So many choices. GL