Actually, I am only going to talk about my iMac in this post, but I thought I'd leave it open for my MacBook or my wife's MiniMac, since I may have something to say about them later. Since switching to a Mac in 2008, I haven't looked back. Perhaps that's not quite true, because I have recently bought a cheap, but new, PC in order to run NetObjects Fusion, a WYSIWYG website creation tool that a few of my sites were built on many years ago, but the PC mostly sits upstairs feeling dejected and unloved. My first Mac was my 13" 2008 Macbook, which still works as well as it did when I first bought it. I often use that one when I'm traveling since it's a whole lot easier to carry than my 27" iMac. My iMac, first of all, has a large screen, but it also allows me to connect as many as three additional monitors to it. Since I don't have room around my desk for three additional monitors, I don't do that, but I do routinely use one additional monitor, and often two, but when I am using two the third monitor is usually being used to play a DVD while I'm working. My iMac came with 4 GB RAM. However, since the way that I work requires me to have a couple of browsers and a whole lot of tabs open at one time, that proved to be not enough so I upgraded it to 8 GB. That did just fine for a few years, up until the time that I upgraded the OS to Yosemite. For some reason, Yosemite seems to be using memory differently than previous versions of the OS. It seems to be allocating all of the available memory to whatever I have running, leaving nothing in reserve for things that I may want to add later. I kept running out of memory, and I wouldn't notice that until it got so low that the critical conditions flag was thrown out onto the field and, by then, it doesn't even have enough memory to boot the app that frees memory, and it would sometimes lock up for an hour or more. It wouldn't crash but I would have to wait for the memory to slowly clear, since there wouldn't be enough even for me to close anything down. When I did notice that the available memory was getting low, I might close Firefox. That would free up a couple of GB of RAM but, within a few minutes, Safari would use that and I'd be in the same position. I never had these problems with any previous versions of the OS. I just got back from the computer shop, where I had my RAM doubled again, this time to 16 GB. If it starts to eat that up, I'll have to see what Apple can do about it. The nearest Apple dealership is hundreds of miles away, however. Although I only had 8GB available until today, my computer is currently using 8.93 GB.