I have used a bivy system for years. It has been very light, versatile, kept me warm & dry and I’m to the point that I can set up fairly quickly. I too have used it in conjunction with a tarp, and a bug screen draped “teepee-like” over the head area if it’s buggy. The bug screen is hung from a cord-- often the cord which suspends the tarp. I use a mountain hardware goretex model and used to use an Early Winters goretex one as well. When I started using this system, a light tent was four to five lbs. I’m now to a sub-two lbs, which includes the bivy, tarp, cordage and a few stakes and screw-eyes (great for making a tie-off point on a log or tree or root). So, it’s a very light alternative to many tents. The tarp I’m now using is an Integral Designs “Sil-tarp” which is very light and takes up very little space-- I’ve been able to cram it into a pocket while setting up tarp lines. The tarp is a great idea even for tent-camping. We have used it as a group area for eating, cooking and being neighborly in. Otherwise everyone in a party of people stands in the rain together or leaves to their shelters. The tarps don’t work well in a heavy wind, although I’ve managed by stringing it tightly out and closer to the ground.<br>Another plus is that it’s very easy to set up camp in a very small area. I’ve slept in boulder fields where it would have been impossible to set up a tent. Also, in a pinch, I’ve slept in the middle of the trail (caught by darkness).<br>Minuses include not sleeping with my wife if I’m in the bivy-- That may be a plus in some marriages at some times-- She insists on a tent. And, I must admit that some of the “tarp-tents” which weigh very little are looking attractive. Integral Designs also is a good place to look at-- REI sells some of their products-- but they are as if not more expensive than many of the more traditional tents. <br>Be aware that the listed weight on many of the tents does not include the stuff bag, stakes, cordage for guy lines-- also that the listed weights may vary quite a bit from the actual product. Be sure and check out Blueline Outfitters and see if Barry has any bivys. I prefer the basic bivy without any loops-- I'm usually with a tarp remember-- they are lighter as well. I've never used the Hennessy Hammock but I'd like to give one a try someday.<br>:v) Good luck and drop me a message if you've got any Q's & what you decide on.<br>9-fingers (a sappy bivy lover)