I really like my Zpacks tarp. I have the one without a bug net, claimed weight is 4 oz. This weight doesn't include stakes or seam sealer, but still well under a pound for the whole thing. With a tyvek ground sheet cut to size, it works quite well. I have yet to subject it to really bad weather though, rain with variable strong winds could be uncomfortable:
Can you give an update on how the tarp is going? Do you regreat not getting the mossie net included?