Beta Light -- indispensable tent replacement
The beta light should be the shelter of choice for those that travel with trekking/ski poles. I have used mine for 4 years with 50+ days per year. It is light, weatherproof (as long as you take the time to seam seal it well with syl-nylon seam seal), compressable, and very secure. I have used this thing in winter, summer, high winds (Mt. Rainier) and the only place where I wish I had a tent is when there are bugs (you can combine with the beta bug, but then it's nearly as heavy as my tent).
Pluses -- wickedly light, easy to setup, and well designed
Minuses -- If you are base-camping, you must collapse your shelter to use your poles each day. Must be carefully seam-sealed.