Timely post. I'm considering doing a '62 set and was wondering this week whether doing the GT distinction was worth it at all. I had long speculated that graders even had trouble telling the difference. Is there a primer somewhere that someone could point me to on what is a GT and what is not and how to tell in cases where there are subtle differences?
As a funny aside, I remember an old quote where Mr. Mint Alan Rosen supposedly said that green tints were "stupid and ugly" and not worth collecting.