We hired NuView to replace almost all of the windows in our house and to put flashing over the windows that we didn't replace.
They came out almost within days for the quote, which was a bit high. We chose to go with them anyways as we were convinced about the quality of the product as they were recommended to us by our neighbours.
Because the windows needed to be made to order, it took 2 months before they could be installed and then because of our holiday schedule, was delayed a month further.
The window installers were quite fast and professional. They noticed a scratch on one window when they were being installed. We are still waiting to have it replaced (3 months later).
Overall, we were happy with NuView and would recommend them if you were looking for very well insulated windows.