I was going to manually obtained the .gcd file and do the update. I'd picked non-MTK because I didn't know what my 255W was. Only after I decided to be "safe" and use Garmin Express that it picked the "correct" file. I did post analysis and found out that the unit was MTK based on HWID from .xml !!!
Lets say after identifying the unit and getting the .gcd file from perry, what do I do next to update the unit? Do I have to convert it to .rgn and use Updater.exe? Or can I update the .gcd file directory by just putting it under Garmin directory and reboot? Which method is "safer?"