Bigger Tiles is critical
The Bigger Tiles plugin in particular is absolutely critical to performance. Using Photoshop CS4 11.0.1, I measured these bizarre results with and without Bigger Tiles on both a 2.8GHz 2008 Mac Pro and a 2.93GHz 2009 Mac Pro Nehalem. I confirmed with Rob-Art at barefeats.com that same behavior; the culprit seems to be the Smart Sharpen function, which runs far more slowly without Bigger Tiles.
I ran into this page yesterday and since installing these plug ins CS4 has stopped it's constant crashing. Oh man, I spent hours on the phone with Adobe tech support and never got a good answer. I rebuilt this system from the ground up to try and resolve the crashing. So if you have problems with Photoshop CS4 crashing constantly, try installing these little guys.
On a side note, some other things I have recently learned:
Itunes Genius function will crash your itunes on launch if you are not connected to the internet. My ISP went down on Saturday and that meant no music for me since it would not launch. Turn that crap off. Good luck on turning Genius off if you have no internet by the way.
If you highlight a word on the New York Times web site you will get a little question mark that will open a definition of that word. Pretty slick.