The only downside for me in using the unlock map reverser is it creates an extra mapset and takes up more room. You need to be careful which mapset to remove from your system. The latest map reverser version is 4.2 and the developer is screening people before he allows them to download now because he claims it was being used for illegal purposes.
However, the simplicity of using the ALL. Bat file and the fact you can make a fully transferrable unlocked .img file is phenomenal. I will use this method until it's no longer possible.