It seems quirky. It was in my shirt pocket yesterday for a motorcycle ride which was about 250 miles round-trip. Outbound it worked great, the return trip was spotty. Sometimes it locks on in seconds, other times it takes minutes (with a clear sky).

It is fairly sensitive and accurate and tends to stay locked as long as it gets a signal.

It also doesn't consume much power. There was no visible battery drain from 3 hours of use (I wrote zmapper that turns it on and logs the GPS stream to a file even when the map program is off, so with only the GPS active - no other programs I probably could have gone the whole day, but I had a USB battery pack to top it off).

That said, I think a BT GPS (for $50-$70) would be better since you can position them in your backpack or whatever where they will see the signals better, and they have better antennas - size matters and they can't put a real strip antenna in an N810.