I took my unit in today to be modded to an N3. The guy who does the mod's told me to watch out for downloaded ISO's because there's one out that will fry the GPS capabilities of the unit when loaded. He also told me how to tell the difference.
He said that when you first load the software, if the screen says 1/1 instead of 1/2 when the loading first begins, you should cut off the unit immediately or it will corrupt the unit. However, I have been running N3 software on my N2 for quite some time and I also acquired it off of a .torrent. However, it worked perfectly fine.
I hosted the .torrent myself for some time, and also created the first .torrents of the v1.2 of the N2 software (50MP I believe). I still have the image file on my PC and if there is an issue with the .torrents everyone here is using, I will recreate a torrent and post it up so that a working copy can be utilized.
Note, as I do have both the East and West disks, I loaded my copy utilizing the East DVD and have not in fact burned and used the West DVD.