This device is really close to being a great product.
However, the lack of support and decent documentation let it down, to the point where it is difficult to recommend.
For example, the manual tells you have to set the APN name for a GPRS connection, but not how to set that APN's user and password. Also it doesn't seem to be able to continuously (say once a minute) send it's position via GPRS (reading between the lines of the documentation that does exist). You have to keep ringing it up or texting it to get it to send it's location. So it doesn't really work as an unattended tracker which is what I needed it for,
Such a shame because the product itself is all there, and seems to work at least via SMS, which is some feat at the price-point of this unit. A few firmware changes and some documentation would have made this a great device.
I should add that I was trying to use this device as a permanently powered vehicle tracker, using GPRS comms instead of text messages, which 'on-paper' it should do but in fact isn't quite there. The text message stuff did seem to work OK as far as I used it, so as a personal tracker (for finding vulnerable people etc) it should be fine, as the other reviews suggest.