The Tipi we used was the new 16-man.  Our team was on a joint project involving both The Explorers Club and USARIEM (US Army Research Institute for Environmental Medicine).  Our team was collecting physiological data during a graded ascent to Mt. Everest Base Camp in the Khumbu Region of Nepal.  Data collected  is being used by  USARIEM to create predictive models of susceptibility to AMS (Acute Mountain Sickness).  Except for our Ph.D. Physiologist from the Army, our team was all self-funded volunteers doing their part to help our fighting men and women in their future field deployments involving altitude.  We were in the field three weeks, trekking about 100km over elevations ranging from 9,000' to 17,000'.  The Kifaru Tipi was transported by both humans and, at higher elevations, by yaks.  The Khumbu region is well known for its hard rocky ground, dusty conditions, snow and strong winds.  This was a genuine torture test, and I honestly believe we put more wear and tear on the tent than most users will in years of use.  If there were any weak point I think we would have discovered them. Overall the Tipi tent rates an unconditional A+ from our team  It is HUGE inside but amazingly (and I really do mean amazingly) lightweight at under 20 pounds. The center pole is a serious military style piece of hardware. There is no way the pole is ever going to break or bend. I didn't know YKK made such huge heavy duty zippers.  The new fabric is very lightweight, but incredibly strong (same stuff as hang gliders?) We did, however,  manage to put a hole in it with a wayward Yak's horn (easily patched with nylon tape). Our Tipi was coyote brown in color, yet let in plenty of light through the fabric. I initially thought this might be a problem, but the material lets in a lot more light than traditional canvas tents, and seems about on par with nylon tents in terms of light penetration.  The design is brilliant in its simplicity. The doors are easily tall enough to walk through upright, and provide an easy way to control ventilation. The tipi shape sheds wind and snow beautifully.   How big is big? At times we had 14 people seated around tables inside the Tipi with plenty of room for extra people and gear. We used the Tipi throughout the expedition as our gathering area, and as our research center. Our Sherpa team and the local yak herders quickly took it over at night as their preferred sleeping quarters. Besides being so lightweight and compact to carry, the next biggest advantage to the Tipi is that the tent is really easy and fast to set up...it takes maybe 2 minutes from the stuff sack into a fully functioning shelter after a little practice. If you've ever tried to set up a big tent in windy conditions you will really appreciate the benefits of the Tipi because it is really fast and easy to erect in high winds. In a high mountain environment with frigid cold and high winds this is a really important feature. I thought you might be interested to know that the same 16-man Tipi tent has already made its second trip to Mt. Everest Base Camp, in May, with another team.  Their reports confirm our observations. I expect this tent will be a part of many tales of adventure and exploration in remote lands over the coming years. In an age of cost-cutting, outsourcing and substitution of cheap materials, it was really great to be able to depend on the Kifaru Tipi.  It was obvious from the moment it came out of the stuff sack that it was designed and constructed of quality materials, by people who understand the rigors of a genuine wilderness environment. Thanks for making such a quality product. The Kifaru Tipi is a great tent ! Sincerely, Scott Hamilton Expedition Leader Mt. Everest High Altitude Research Expedition