I've used had Garmins since they first came out. The great thing about them is you don't have to pre-measure a route, which comes in handy when you're traveling, etc. They are also good for workouts like tempo runs to help with pace. I used to always think they were good for races as well, mostly to keep myself from starting too fast. However after Chicago, I'm not so sure. I knew it would be off from the start, but I didn't know it would stress me out as much as it did. My pace was all over the place because of my reaction to what the Garmin said. I realized I was not listening to my body as much as I should have been. I should have been able to hit my goal pace without using a GPS. Next time I think I'll go with a regular watch and the mile markers.