Rating: 4 / 5
The SpinnTwinn was the shelter for 2 of us during a recent week-long hike in the Grand Canyon. We had three nights of rain, including one night of gusty wind-driven rain. The tarp was exceptionally easy to pitch, and with a little attention, it was easy to produce a taut and very stable shelter. During the two nights of gentle or less wind-driven rain, the tarp proved completely adequate to protect 2 sleepers and some of their gear. However, wind a storm barrels through the Canyon, winds that may be Westerly hit those 1000-foot walls and come at you from all points of the compass. This makes pitching the tarp against the winds a challenge that borders on futility. As a result, it is inevitable that the open ends of the shelter are going to be vulnerable, and they were. Light spray came in, alternating between the ends depending on where the winds came from. The resulting dampness was not serious, but had the rain been harder it would have been more of an issue. I knew this might be an issue, and I had wished that the tarp was another 12-18" longer, and still do. This is a problem that is probably fairly unique to these conditions -- erratic winds and temperatures, even in March, that are high enough to preclude the use of a UL bivy to augment the tarp.
In sum, the Spinn Twinn worked extremely well, for the most part even under challenging conditions. I will continue to yearn for a SpinnTwinn that is a couple of feet longer, but until that comes along, I'll keep the current version as my primary shelter.