When I replaced the original nylon sheet, I went with the polyester mesh because it was
$10 cheaper and I wanted to see if I could forgo the additional, separate sheet that I brought along to deal with the perspiration issue in warm weather. (Skin on nylon == very wet.)
Based on one trip's use out of it -- Century Ride of the Centuries over Memorial Day weekend: the mesh seemed to address the perspiration issue better, so the weight may be less different when you factor in the additional sheet. The polyester
is bulkier, but still fits within the original stuff sack. The poly mesh does not seem as well engineered - the side flap where you slide the poles in is wider (easier to get the poles in), but they slide around more. I had one of the bottom hooks pop out during my first night. It was certainly easy enough to reset, but was annoying.
Would be curious what others' experience has been.