I bought one, too. It was actually not a spur-of-the-moment purchase, though. Since 2003 I've shared discussions with Glen about shelter design and ideas for something like the One came up every now and then. As the Gossamer Gear website alludes to, the development of the One was a long, slow process that took many iterations to finally make it into something viable for commercial release.
I've had my eye on this type of design for a long time and even made several of my own similar designs prior to seeing the first prototypes of the One. I could never tweak the problems just right, though. I thought I found what I was looking for with the Rainbow (which is quite similar as a type of shelter), but I found a number of problems that didn't suit my needs (one of my ideas, the hiking pole grommets in the apex pole sleeve, was incorporated into the final Rainbow design).
I think the One does what I want a shelter to do, especially for summer alpine conditions. It is a very mature design (as most of the UL cottage gear designers will now be moving on to), based on the years of trial and error of earlier UL ideas. When I saw it I knew that it addressed just about every concern I have. The material is time-tested (and GRAY! One concern about the SpinnShelter, though not a big concern, was that it was white), the vestibule is big, it has a side entrance, a small footprint, is wind-shedding, doesn't have unnecessary weight by using a tent pole when I use hiking poles, has a bug screen and floor, uses a zipper for the door, and incorporates good venting. Until I have more experience with alpine tarping this is probably what I've been waiting for and I may never move beyond it. (being an architectural designer though, I'm bound to start seeking new solutions!). It is exactly what I would have wanted when I was in the Alps last year.
I've loved everything I've ever bought from early Glen van Peski gear and later Gossamer Gear and have never had any disappointments in any of the gear (except that the headroom of the SpinnShelter when in storm mode is way too low for comfort, but that's it). I fully expect the One to quickly become my favorite shelter.
Since ransacking for the last two months my apartment of all extraneous goods I'm down to three shelters (after having eight!!!). Now I need just two staple shelters: a good solo winter tent and yet something else to use with my wife. Does ANYONE have any experience with the GoLite Xanadu 1 ???