This device opened up a while new world for me, the information generated together with my Garmin Vector 3 has made me more aware of my baseline and identified areas where I can improve thus making my cycling experience more enjoyable
I got this unit as a replacement for an Edge 820. The 820 had an almost unusable touch screen and I always wondered why they didnt have a 520 with mapping. Overall , the usability of the unit is great. The buttons positively move from one screen to the next in a deterministic way unlike fumbling with the touch screen. The mapping function is pretty good , I am able to upload routes from my iPhone or computer and it works pretty well. The only thing I wish it had was to navigate to a map point without actually physically being at the point and saving it. There is a work around which involves creating a route on a smartphone and uploading it to the unit. But you need a smartphone to do this.
i love using the new Garmin 520, it has everything the 520 has Plus the slightly toned down maps of the 820. overall i like the new maps it comes with. wish the screen was slightly bigger but it fine overall. Also has a slightly updated data fields which look great.