(Forrester has not named the executives or companies it spoke with for the report.) “We’re replacing PCs every two to two and a half years while we push a lot of our Macs to four or five-plus years,” one executive told the survey team. PCs also provide lower usable life and lower residual value, the report claims. Additionally, there were fewer hardware-related issues with Macs and fewer dependencies on multiple vendors to perform each task.