Eric,
Why do you care what these guys think anyway?

It was your decision to make the investment and you sound like you knew the potential risks going in.

So who gives a ****e what anyone of the above detractors think?

In the end only time will tell if you made a good decision. You've indicated based on your experience you are currently ok continuing to wait. And as it's your money it's really no one else's business, even if it doesn't work out.

Certainly some parts of the more rational portions of the discussion above are worthwhile to caution other potential investors.

Personally I hope things do move forward for you. It would be great to see this glider get into production. However only time will tell, everything is pure speculation.