Well, this is a bit embarrassing for Apple. The latest operating system (Mavericks) was offered as a free upgrade but it turned my iMac into a sluggish pig. I hoped that the first version update would fix the problem, so I waited for Version 10.9.1. No better.
A Google search for “Mavericks is slow” revealed that thousands of people were looking for a way to revert to their earlier, better performing system (Lion, in my case).
Good idea, I thought. So I copied all of my files for the last couple of months, saved them onto a backup hard drive and reverted to a pre-Mavericks backup From Time Machine. To do that, you have to restart the computer while holding down the Command+Option+R keys. You are given the opportunity to restore to a previous date from your Time Machine backup.
The process is a bit intimidating because your whole hard drive gets erased, then rewritten with the contents of your chosen backup. Took a couple of hours. All of my Adobe products ceased to work and had to be reinstalled from disks, then updated. Took about 4 hours including calls and waiting for Adobe to untangle its inconvenient anti-piracy obstacles.
When Apple eventually admits that it made a mess with Mavericks and fixes its mistakes, I’ll upgrade again. Before that happens, though, I’ll do l’ll do plenty of checking about other user’s experiences.