I recently had some problems with an SSD because Scannerz would keep picking up bad blocks. They would disappear eventually but in the long run as the system did it's clean up, but they were becoming rampant. I ended up having to return the SSD to the manufacturer now it seems OK. (http://forums.macrumors.com/showthread.php?t=1797868 for reference). In any case, when I was having problems a friend came over with his Power PC based Aluminum PowerBook running Leopard. This is what ticked me off: The system booted in 30 seconds with an old HD, and my system with Yosemite and an SSD was booting in nearly a minute Everything loaded faster. He could click on Mail and Safari almost simultaneously and the were up and running when all I get with Yosemite is a spinning beach ball and about a minute wait I just think the classic look is better looking. I can't put my finger on it, but when I look at Yosemite I think I'm looking at an OS for kiddies My question is this: How far can I regress OS wise without actually having some type of compatibility problems. I know I can't go back to Leopard because my system doesn't even support it. I can go back to Snow Leopard though. If I were to move this far back with an OS, would Safari work right? SL's getting old and I know that my friends version of Leopard has a Safari that won't properly open some pages. If I revert, and not revert back to Mavericks but waaaaayyyy back to something like Snow Leopard, what problems might I encounter. I'll be honest. I just don't use any of the features Apple added in a lot of their OS releases. I could functionally live wiith Leopard.