I think what he means is that if you want to customize the displays with which metrics you want, how large, etc, you have to do it directly on the Garmin, vs. with an app. with the Bolt. My Edge 500 is a *little* cumbersome setting up screens, but not that big of a deal.




But if offers *way* longer battery life, probably in part because of the black & white. Apparently the 520 only runs about 4 hours and change in navigation mode. That's a deal-breaker for me because the rare times I actually use navigation are on 6+ hour epics (which my B&W 500 has kick-ass battery life). The colors do look good. But the ~4 hours battery life isn't worth it for me.

Edit: Huh. Comments below the link I posted have some people saying the 4 hours is not accurate. and the 520 can to up to 15 hours of navigation.. But they also say the navigation on the Bolt is far more felixible. E.g. on the Garmin you have to upload a route file prior to the ride. With the Bolt you can just whip out your smartphone mid-ride, set a destination, and your Bolt will take it from there. That's pretty cool.