Daryl, I agree about the weight and the snagging. The snagging should be a little less irritating with the netting than it would be with mesh, because the netting won't tear, but it still might be an annoyance.
I initially felt conflicted about the cost in weight, but I have decided that I'm willing to accept it. The netting itself is basically 200 lb test dyneema fishing line in a grid of 1" squares (it is actually marketed as fishing net), and it weighs about 1.3 oz/yard. I'm considering using a 1.6 oz/yard dacron pack bag underneath, and a thin liner inside that. This brings the total material weight up to just over 3 oz/yard. This is still lighter than Dyneema Gridstop and some of the Dimension Polyant pack fabrics, and the pack should require less than two square yards of each material, so the absolute cost in weight of the netting design over 1.1 oz nylon is probably less than three ounces.
I plan to use a mesh-like high-tenacity nylon from a fencing jacket for the bottom, 1/2" thick 3D spacer mesh for the back, and pocketed straps that will hold 2L of water, so it will definitely end up much heavier than your packs in the end. I hope to keep it under 16 oz.