Anyone have any positive or negative recommendations for such a device? It needs to be precise
Well go with Nikon, at least you can plug a gps into the camera, with Canon you need to time sync with the gps then run it through a third party program to match image and gps up. For me using Canon it just does not work well, I am usually travelling in a helicopter or light aircraft . I am sure backpacking or moving slowly it's spot on, but I have given up jumping through hoops to get this to work accurately, I could spend a fortune on a wifi unit to plug into the camera that will then take a gps. But I don't know how well it works, it's bulky and I use three cameras. I don't mind buying three gps units, but three wifi units is over the top.
My iPhone can shoot and tag an image, my Wife's point and shoot can tag as well, but not a top of the line Canon, pretty poor of Canon I think. My old Kodak SLR/n could link directly to a gps.
I would have to say don't go Canon if you want gps.
Kevin.