My old Garmin Edge 305 died last season, and I was reluctant to replace it. Sunday, however, I cashed in some Christmas gift cards and my member points at REI and purchased the Garmin Edge 500. I've used it Sunday, yesterday and today. It's very quick at start up, allows me to put the information on the screen that I want to see when riding, and downloads to my laptop efficiently.
Being somewhat skeptical about the accuracy of the mileage, speed, etc. I used my smart phone's My Track program, my cars GPS and the 500, and took a short 16 mile drive around a route I've cycled for years. All three devices and the car odometer were reading the same distance, and all three devices were reading the same speed.
Another cool thing is that the heart rate monitor and cadence sensor for the old 305 will work with it. And, while the unit will gather much more data than I'm likely to use, one of the strong points for me is the new easy mount system. It's a snap to move the unit from one bike to another. By the end of the week I should have a mounting system on all of my bikes. One computer for eight bikes.... I'm really loving that part.
I just hope it's more reliable than the 305 was.