We've heard this from several people (hence this FAQ entry). To be quite honest, we don't really understand why.
We read online all the time about condensation inside the RV windows, and the responses are usually recommending dual pane windows. To be fair, we've never had single pane windows, so we have no point of comparison. However, we can say that we've camped in all kinds of climates all over the US and have never had any condensation.
So, yes... We still stand behind our decision to order our dual pane windows and will have them on any future RV also.
UPDATE (May 2021)! We recently ran into viewers of ours in an RV park and somehow got on the topic of dual pane windows. They had an interesting situation where one of their windows needed to be replaced and it was erroneously replaced with a single pane window. Shortly thereafter, they saw they were getting condensation on the inside of that window. This picture clearly shows the difference dual pane windows can make in an RV!
Thank you to Brooke and Jeff (@behappedesigns) for allowing us to use their photo!