Are these good quality tents?

I was recently out shopping at one of the outdoorsy type stores, and I saw that they had a sale on Sierra Designs tents. I need a new tent, so I am thinking of going back and getting one of these, but I wanted to find out a bit more about them first. Are these good quality tents? Are they worth the money? Is there somewhere I can go on the internet to learn more about them and what people think of them? I would really love to find some customer reviews listing the pros and cons of these tents.