I've had my 24", 2.4GHZ, 4GB RAM, late 2007 Al iMac about two years now. It's running SL 10.6.2. There's really nothing wrong with it. I repair permissions every couple of months. That's all the maintenance I do to it, besides letting it run its own maintenance scripts. I do a full shutdown every couple of weeks, and sleep it the rest of the time. It seems to have lost a bit of its speed over time. Any recommendations between TTD and OnyX? Do they both do about the same things? Thanks in advance for info/advice. I've never used either product before.