Seeking info on vacuum-insulated glass units – GreenBuildingAdvisor

I have been searching on the web for information on vacuum-insulated glass (VIG). I know Pilkington has been offering them for a few years, in the R-5/U-0.2 range, and I can see that there are lots of other websites of companies that say something about VIG, but it’s kind of hard for me to tell which of these companies is actually offering VIG as a real product right now, and how many of them are simply talking about it as something they’re working on. Part of the problem is that most of these companies do not sell windows (they only sell the glass) and they don’t sell directly to consumers — plus they are mostly terrible at answering emails and phone calls — so I’m kind of at a loss for reliable information about VIG. 

My personal interest is in buying the VIG units and putting them in historical reproduction wood windows and/or wood storm windows, as opposed to buying a full window. I’m trying to create a historic look that would make people like Brent Hull proud, while minimizing the performance hit that usually comes with windows of any kind.

I would love to see a full scale article or series of articles about vacuum-insulated glass on this site. I’m definitely not the right person to write that series. I’m just someone who could really benefit a lot from it!

Does anybody have information they can share or explain? I know in theory that VIG is supposed to be able to reach R-20/U-0.05. or more, and I’ve seen some claims of R-18/U-0.056, but is there actually anyone out there who sells VIG at those values?