I have had licenses here for up to 6 computers running Parallels Desktop 4, 5, 6. Now at least 4 of them are upgraded (yet) to version 7. I don't know (yet) how it goes on older Mac hardware, but on relatively recent (core i5/7) hardware with decent RAM (4/8 GB), Parallels Desktop 7 for Mac runs **extremely** well (performance improvement **is** perceptible on various areas). Especially I find the Coherence mode performance to have reached a perfectly acceptable level. Suspending and resuming is nearly a snap (at least with my guests Windows 7 64 bits). I am sure I will find some bugs along time -- you can't expect anything else from such a complex piece of software -- though for now the outcome is bright. Ultra bright.