I have one of the Gear Guide tarps, known around here as the neo tarp, and it does great. Yeah it's a little heavy and it does have some sag issues, but I used it on about a dozen outings and it kept me dry and comfortable. You can't beat it for the price.
“Light thinks it travels faster than anything but it is wrong. No matter how fast light travels, it finds the darkness has always got there first, and is waiting for it."