Well, since you asked...Hell YES I've noticed a difference!
Web browsing is slower indicated by the fact that the little spinning wheel next to the mouse/arrow is active MUCH more than ever before. From my perspective, 10.5.7 was a step BACKWARDS. I've tried with both Snafuari 4 beta and Firefox with the same results. Interestingly, Firefox inside of Windows 7 under Fusion is FASTER that Firefox native on the Mac.....go figure.
LOL.
And I am not the only one seeing the phenomenon.
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2008 2.6 ghz 17" MBP, 4 Gb ram, 30" ACD, 4 Tb external storage.