I own a GoProHD 1080p and ContourGPS.

I like the GoPro better. Reasons?

-- the video quality seems a bit better
-- parts and accessories are cheaper (bike mount? $20 GoPro, $30 Contour, and that 50% premium for comparable parts is pretty typical.)

A few flaws with the ContourGPS to mention --

-- the GPS is really bad at getting a lock. It requires a much clearer view of the sky than any modern GPS I've used and takes longer.
-- it gets quite hot when just the GPS is on, telling me it's sucking the battery down.
-- you can only select between two preset video modes out in the field. To change those two modes, you have to connect it to a computer or use their iPhone app.
-- the iPhone app sounds neat -- it uses bluetooth and you can see what the camera sees and configure it from the iPhone. But it requires an extra $30 card to be added to the camera before this works.

However, the ContourGPS does save the data you're likely interested in -- once it finds the satellites, anyways. You could do that with an external GPS and the GoPro if you had the clock set precisely, but it's a lot more work.

I've never tried the other versions of the GoPro.