The silicone nylon is very light and stronger than the plastic
but is slippery as a ground sheet, tyvek isn't so slippery but
isn't as waterproof.

So there are some trade-offs with each one.

A full length closed cell pad with no seperate ground sheet has worked for me. I put boots
and rocks around the perimeter to keep from rolling off.

Some folks like bivy sacks in stead of just a ground cloth to
get bug and wind protection too.