I spoke with the Home Depot "Coordinator" today and asked if the 6500 series was a) Argon, b) double strength glass (both panes), and c) uses the Super Spacer. This was a 3 way converstation with the Home Depot "foreman" that will show up here on Friday. He said yes to all the above... but it wasn't terribly convincing the way he said it.
I sent an email to Simonton and they replied that since I am working with Home Depot on this, they would not give me any data about the Series 6500 which is private lable to HM. So at this point, I think the lesson here is that if it isn't in the literature, and isn't elsewhere written down you may not be getting what you want.
My next call or email is going back to the "Coordinator" and asking for written confirmation of this before we get the order set up.