Received it in the mail today. 14 days from China to Czech Rep, that was excellent! They've provided tracking number, so I knew all the time where my parcel was. Inside the box, there was a personalized letter (Big Thank You Bryan!) with instructions on how to calibrate it, how to recharge it, what leds mean, etc.
I mounted it on my D700 and went out to a park nearby. Got a signal lock (1st time cold start) in less than 30 seconds. Pretty impressive, considering I get a cold-start signal lock with my Coolpix P6000 (which has built-in GPS) in a good 3 to 5 minutes. It tagged my pictures with extreme accuracy, and I was really surprised at how good it is.
I did not switch it off as I've entered the building. I’ve thought to test it inside as well, to see if it beats the GPS in my P6000.
…and just as I’ve expected, it did not. It gave me some strange readings, and the path I’ve got from the tracing file from the MicroSD card looked really weird in Google Earth. And as far as I'm aware, there is no GPS unit to ever work indoors. It doesn’t matter – as I did not buy it for indoor use anyway.
What actually convinced me to buy this particular unit instead of the most expensive Nikon GP1 (which does not provide route tracing, by the way) was this in-depth review, here:
http://www.pixiq.com/article/geotag-your-nikon-photos-with-affordable-gps
And also this YouTube clip:
I’ve bought mine from here: http://e-geotag.com/products/gps-products/easytagger.html