Just looking at this again and I'm giving some serious consideration to the 500... but there are three things I'm particularly interested in which you might be able to help with.
1: Does the latest firmware have the ability to set the device to 1 per second recording? I've read around and think that's the case, but can't tell for sure.
2: If you input a course, can you get it to show you directions with an arrow / compass, or is it via that annoyingly small triangle and breadcrumb trail?
3: You probably can't help here, but I'm a little concerned about durability. Have read a couple of posts by mountain bikers saying they've had the screen crack. Hopefully that's something they've refined on newer models.
Thanks.
1) Yes
2) I don't use courses, but from what I can tell from instructions it is an arrow and a tiny map, from what I've heard the 800 is vastly superior in this respect, I decided it wasn't important enough to me.
3) Don't know, It is plastic, I've dropped it without issue, doesn't seem overly fragile.
The speed sensor however, broke because it got pushed into brushing the spokes. It physically looks ok, only got close enough to the magnet to start making noise, but the sensor no longer registers. Not sure I've ever seen a sensor so delicate, perhaps just a manufacturer defect.