I am a noobie on this forum but have been following this issue, as I own one of the affected 5D iii's. From what I can tell on reading up on this issue and reading the forums, I too am in the camp that this is a non-issue and will not affect my photos. However, it is still disappointing to spend 3.5K on a camera and then have this happen. This was my jump from crop factor to full frame, and I trusted Canon. Not saying I don't any more, but I still don't understand it all.
So a technical question, and likely a dumb one - does the leaked light just hit the light meter, or does it also hit the sensor?