I went out riding today with a Garmin Edge 500 and an iphone both tracking my ride.
Here's the results from the Garmin:
http://app.strava.com/activities/51174112
And here's the iphone:
http://app.strava.com/activities/51172624
For a company that likes to claim it's the best in all things GPS, I was pretty shocked at how bad the Garmin was. Especially since the Garmin was on the handlbars, and the iphone was inside my rucksack.
I rode the same trail just to the west of Reigate Hill on my outward and return journeys, so the outward and return traces should have been right on top of one another.
But, the traces the Garmin generated were a long way apart. The traces from the iphone were much better, and pretty much bang on top of each other, just as they should have been.
The iphone traces on the road sections also match the roads on the map, whereas the Garmin traces often don't.
And the Garmin also failed to match some of the segments on Strava, whereas the iphone caught them all.
Iphone: 1 Garmin: 0