I admit to having problems with the concept of 'oppositionally more slowly' though I understand the syntax. But, are you(or the techs) speaking about available system ram , process memory footprint, image size,or what? Leopard has a max memory limit of 4gb per process, unless it is a 64bit application, which I don't think Painter is. I got a 4core version of the new mac pro so I could afford 10gb of ram, allowing multiple memory hogging applications to be open and happy. So far, albeit with limited testing, I don't see any slowing of Painter. Has anyone tried large complex creations on leopard?