I would give them four and a half stars for quality of work, and that is only because one of the windows was mis-measured and had to be reordered causing a delay. But they made it right. Otherwise, I'm very satisfied with their work. We purchased an older home c. 1949 which had dual pane windows updated about ten or fifteen years ago. Some of the Milgard windows had broken seals, which D & D Glass Works replaced. Some were broken and needed replacement. One had a broken mechanism so the window didn't open properly. D & D Glass Works performed good quality work. I would highly recommend them and already have done so.