We purchased Winchester's Bristol replacement windows in December 2010. At that time, the installation company's website (ResCom of Auburn, MA) claimed savings of up to 47%. The sales rep also claimed such savings. Checking the website a few months later revealed that that claim was no longer posted on ResCom's website. The windows did not, repeat did not, produce any savings for us over our old windows. The windows were rated well enough to obtain the then tax credit for energy saving installations. I wish we had had our thermal imaging camera at the time of purchase, as the frames are colder than the glass is. The installation was also a disaster, to add insult to injury.