Interesting post. Our 5'er has SPW's. We wrestled with the SPW/DPW decision when we ordered our 5'er in 2003 and decided on SPW's. We've been in sustained sub-freezing temps as low as 12 degrees F for a few days at a time during our travels and never have we had water running down our walls. Or the windows for that matter. There has been on a rare occassion (12 degrees F in Iowa & NY for a week each) when we'll see a little frost buildup on the inside kitchen window but it's not enough to generate much in the way of water run. Guess we're just lucky.
Happy camping!!! See y'all down the road!!!:)