I saw them at the Topeak booth at Seattle's recent Bike Expo and when I touched that band of material (I do believe it's called the "AirSpan system with compress-free zone"), and gave him a questioning look (as I'm leery of seams, ridges, even edges of material in that strategic area), he said that it doesn't cause any issues...
I didn't get to sit on it though, so I'm interested in women's reviews too.