[JandC]

We never had dual pane, or sealed windows on our 2 Montana fivers. Our DP came with them so now we have some experience having them.

Since the driver's side window on my present rig is an opening slider it is the only window that is NOT a dual pane. There is a huge difference in the amount of radiant heat that comes through that window when we are in warm areas. In addition, on chilly mornings I can tell a noticeable difference on cold air around the single pane.

Can't really speak to the noise reduction issue since I can't compare Montana's with them or without them. I do know in a residential application they make a big difference in noise reduction.