FWIW I still use a 2011 Mini and my fiancee's laptop is a 2009 MBP. The one thing you need to know is that, just as with Windows, occasionally, you must reform

FWIW I still use a 2011 Mini and my fiancee's laptop is a 2009 MBP. The one thing you need to know is that, just as with Windows, occasionally, you must reformat your machine and reinstall the OS clean. Do not migrate your files & settings. Backup your files, yourself, manually, by hand. Clean install the OS, reinstall the apps you need, yourself, manually. Then copy back your data. If you use an automatic backup tool, it also brings all your cruft back. Don't do that. Do it by hand and only keep the stuff you need, not what some automatic wizard app thinks you need, because they don't think. It is, in my experience, much less of an issue with Linux. Helps there occasionally, too, though. Old Macs are still perfectly usable if you do your housekeeping. They have not mystically slowed down over the years or anything.