It's not just about optimization though, even though Tiger might have more optimization, it's also got a whole heck of a lot more unnecessary stuff to make up for the "optimization." Even when they aren't loaded, dashboard widgets remain in memory, and the Spotlight, noble an idea as it is, really does reduce performance for those of us who are actually capable of organizing files on our computers properly.

And no, I don't want to spend any amount of time optimizing Mac OS X, I don't really think you should have to these days. So for me, it's 10.3 on the G3 system.
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