Poncho Tarp recomendations or comments?

If you are going to use a bivy, then a poncho may provide enough protection. GoLite, Sea to Summit, Integral Designs, and others make fairly typical ponchos that can double as shelters. The bivy is needed because they don't give good full coverage and you can get wet from shifting winds and splash. IMHO, you want maximum coverage/weight in a poncho. The differences are small– fabric type, a few inches this way or that, or the hood construction. All said and done, you are going to get a small flat tarp with a hole for your head and the hood. You get a minimal shelter and an additional 6-12oz weight reduction because you don't need a rain jacket.

The SMD Gatewood Cape will give the same or better rain coverage as a poncho, plus a 35sf tent with 360 degree coverage. You don't need a bivy for rain protection, although the bug bivy is nice. You can pitch the Gatewood tight to the ground in really nasty weather, with some loss of ventilation and space. There is a lot of vestibule-type room for your pack and boots, or a dog.

I like ponchos as they keep my pack completely dry. They are sloppier in the wind. With a poncho as shelter, there is that gap between pitching your shelter and having rain gear. Your windshirt might fill the gap, or wear a garbage bag, or wait it out. They don't look as stylin' as a $400 Dead Bird rain shell, but they will keep you dry.

At 6'1", I won't use a poncho-tarp other than my Gatewood. Rain frequently changes directions on me, so the 360 degree protection Dale mentions is what I prefer.

Given my height it isn't spacious (lengthwise), but adequate if use the panel tie-outs on at head and foot. Plenty of room widthwise. Ingenious design, if you ask me, and supremely functional.

As raingear, I'm sure you know the advantages & disadvantages of ponchos. Great article on this site about 'em too. One thing I appreciate about the Gatewood is the front zipper for ventilation. Way nice, and if you're in a mild breeze it's downright nice in to limit overheating.

I really liked the Gatewood as a shelter, but I gave up using a poncho. I switched to the Wild Oasis because of the similar design and it has mosquito netting. It is a spacious one person shelter.

One insight about the Wild Oasis: if you're in an area w/ fire ants – those little buggers find their way in! The Serenity net tent works for me. If not for those guys, I'd probably be a Wild Oasis user, myself.