I'm considering a new bike computer and this has got me wondering... is this really a good deal when an edge 520 can be had for the same price? I mean it was good in it's day but I'm struggling to see what it offers over a 520 now?
Routing via .gpx files, which is marginally (definitely marginally) better than .tcx, even once you mess with the file to 'prepare' turn-by-turn.
Additionally, being able to get the Garmin to create a route for you whilst out and about.
Personally the above two things are such low priority for me that I'd go for a 520 instead... However, the third difference is a bit more of a big deal (not enough to make it an obvious choice though):
SD card support so you can have the entire UK mapped in full detail. Not possible with a 520. May not matter to many and simply requires a bit more hassle to prepare when travelling.
edit:
If you're getting something new I'd look into the Elemnt. Similar to the 520. Worse in terms of no colour maps. Better in terms of support from Wahoo (way more responsive than Garmin, at least for now) and also some awesome features like auto-sync of routes from Strava route builder. This particular feature is enough to tempt me away from my 810.
