Shame the insights were innacurate!
I'm afraid you are mistaken, PM has always been, and remains, the fastest browser going, and nothing has changed. Sure, CS4 Bridge is much more nimble that it used to be but it still cannot keep up with the immediacy of PM. I am fully aware of, and understand, Bridge's capabilities thanks, and PM remains the most useful tools for the task for which the OP specified.
Q: Have you actually tried to browse a nice big fat folder with both programs? To make sure I'm certain of my facts I just did that and on a folder of about 100 D3 NEFs Bridge takes about 5-6 secs to show the first image at 100%, and 3-4 secs for each image thereafter - and that's using embedded previews. PM is more like 1 sec per image, at 100%.