I initially found out about Ultra Windows on an online forum while I was researching both windows and installers. I know from experience that any good product can be installed wrong. The glowing reviews of this company's installation procedures were what convinced me. The overall stress-free pitch and actual recommendations of product, rather than "selling" it, convinced me to spend the slightly higher price for the windows Ultra recommended. Installation was done very well, with a very respectful and informed crew. These guys had our 18 windows installed in two days. Overall, highly recommended. (The neighbors have all complimented the drastic change.)