Bests & Worsts Reviews from Amazon

I bought this unit to allow me to geotag photos from an upcoming trip to the Grand Canyon in a couple of weeks and to the Dominican Republic later. I attached it to the shoe mount of my D-90 first, and then to the shoulder-strap mount (included). From a cold start right out of the box, it locked on to at least 3 satellites (solid green indicator) within 30 seconds. Afterward, it required no more than 2-3 seconds to get a locked. It records latitude & longitude (d-m-s), elevation (m), and UTC date/time. I examined the test photos using the Geotag feature of Nikon's View NX photo browser, which connects to Google Map / Satellite. The tag was within 10 feet (if not exactly on) of the spot where I snapped the photos. Update: After several days of use, I'm very pleased with this device. However, be aware that the unit is powered by the camera's battery. There are two power modes - ALWAYS ON (as long as the camera is on) & AUTO METER OFF, where the GPS shuts off with the automatic shutdown of the camera's exposure meters (to preserve battery life). The downside to the AUTO METER OFF mode is that you have the give the GPS time to re-acquire a satellite lock before it will tag your photos (in most cases, a few seconds). Because of this, I like to set it for always on - I want it to be ready to tag whenever I'm ready to shoot. The downside of this is if you forget to turn your camera off when you're not shooting, the GPS will drain your battery. In other words, be sure to have a fully charged second battery.