I just got another reply from Ron that sheds some more light on this. So it seems this is not a case of manufacturing variability, but a case of changed materials. You were "lucky" to get your NetTent from the old batch with weights of 14 oz. Mine weighs over 15% more, but hopefully will be "more robust and less subject to fraying and running". Now SMD just need to update their website to make sure other customers are not as surprised & disappointed as I was.
A while back, we made a change in the mesh being used. We were using two
kinds of mesh but as they were similar, it was causing confusion in the
production. To stabilize production and ensure consistency, we opted for a
single mesh. The new mesh is slightly heavier but is more robust and less
subject to fraying and running.
If we ever find a suitable lighter weight mesh that has the
characteristics that we want, we may adopt it. We didn't update the
website because the decision to make the change was done months before the
production of the Haven NetTents and by the time we received the
production run, we'd simply forgotten.
The website will be updated to reflect the changes. However, due to the
number of changes that are required in all of our product literature, both
printed and online. It's not likely to happen until we do our next round
of updates for the 2013 season.
We apologize for any inconvenience but at the moment we simply don't have
any of the older stock available.
Six Moon Designs
Innovative Ultralight Adventure Gear