We just purchased an Eichler in San Rafael with mostly original windows. We have two young children and are concerned about both safety and insulation. We are debating whether to replace the windows or put a protective film on them (it sounds from these postings like the other option -- acrylic inserts -- are no longer locally available?). Has anyone used the window film? What is the cost differential for replacement vs. film? Any recommendations on companies to install replacement windows?