I was apprehensive about getting this due to Garmin's track record of having software bugs that take multiple version upgrades over a year or so to work out, however this one so far seems to be right on arrival. Mine came with version 2.4 which worked fine the first few rides. A new version was available (3.1) and I allowed the upgrade and it still works great. Zero issues. The mapping is nice and the touch screen while perhaps a little more sensitive than the 510 is not an issue for me, and it's actually bigger than the 510 while the body is smaller. Being smaller is possible due to the location of the buttons for startstop and lap being on the bottom edge, not the screen plane bottom like the 510. The location of the buttons with a KEdge mount does make it a little tighter getting to them because there isn't much room between the bar and button to stick your finger in, but you just need to bump the switch lightly so it's not an issue for me. I like the auto dimming screen too. Auto upload is nice. It will be interesting to see what IQ apps are available in the future for this. There are some interesting ones with quite advanced training metrics to use during a ride. Some are free and some you will need to pay for. Right now, very happy camper. I'll update if I have any issues as I get more use with it - right now I've had it a week and have about 200 miles over 6 rides on it so admittedly limited data.
I really like the idea and it picks up around 95% of vehicles approaching from behind. It doesn't usually pick up cyclists but I've noticed it does recognize some larger steel bikes as vehicles. It's not the brightest of lights but I think it's bright enough to be seen. My main complaint with this unit is how it drains the battery on my Garmin 520, I've turned the backlight all the way down but I still struggle to keep my Garmin going for longer rides. I would definitely purchase it again and would recommend it for rural riders.
Got this for a trip in Europe. Loaded routes, and it was very easy to follow. Only downside was that I needed to buy the Europe map. Great to have the Russian GPS system as well. Great service at Western!