My research hinted that they might have manufactured them into 2003 or so. I was not aware that SA was 'turned off' by the Gov't or somebody! The manual I downloaded vaguely states accuracy to within 15 meters. That's not as close to GZ as I was hoping for.
Most reviews are in favor of the GM100 as a good starting unit. I am being given this unit so I have to try it at least with my kids first. Then, dependent on how fun it is or interesting for my kids and family, I will look into buying something new.