I have an Edge 810 and am thinking of getting a Garmin VIRB. As I already have a Garmin GPS, HR and Cadence sensors can I pair it up so that the VIRB gets all of the data from the 810 for the overlay?

Just seems daft having to buy the elite with GPS when I already have a garmin GPS on the bars?

Yep, the Garmin software will merge all the data together for you. You may have to manually adjust it with an offset (which you wouldn’t have to do with the VIRB Elite).

Excellent comprehensive write-up on the DC Rainmaker site http://www.dcrainmaker.com/2013/12/garmin-depth-review.html

You can also use a “now free” bit of software to do your GPS video overlays. I use it with a GoPro and stand alone GPS unit XGPS160/Edge 800

http://www.dashware.net/
Now free as GoPro has bought the company.