Seeing as the increase is so noticeable (I recently used Norton 6 to defrag my G3 and 8600), I don't understand why apple hasn't bundled a defrag util with ANY of their OS releases. But that might very well put Norton Utils on the chopping block, cuz that's the ONLY reason I paid for it, for the defrag util.
Yeah, the increase is phenomenal, especially launching/using Classic and all the little frivilous animations of the OS. Lovely stuff. I'll put it to you this way - running 10.0.3 on my 8600 became about the same experience as using 10.0.0 out of the box on my G3 - with the sad fact that QuickTime movies are a lil' choppy. Oh well, I'm sure Puma will fix all this... i'm dreaming of July 17th and that lovely little Software Update window pulsing happily at me.