For those of you who have, for the most part, had problems, this question is for you. Many people swear by their choice in windows but some swear at them. Some say you get what you pay for and of those I've heard Anderson or Pella are the best.
I'm going to be building in the coming years and will most likely specify a low-e windows. The best judge though is time. If you have had horror stories with windows and would like to advise to avoid a certain make or manufacturer I'd love to know what happened and why you would never buy them again especially if you have had long term experience with various manufacturers products.