Yes, 3-4x Slower
When I have to wait 3 or 4 seconds for things to happen in Word (like cutting, pasting, or deleting text) that used to happen in a second or less, then yes, I call that 3 or 4 times slower.
And that's just Word. What's worse, in terms of sluggishness, is iCal and iSync. If you can explain to me why they are many times slower than Palm Desktop and HotSync, that would be great. I know people say it's version 1.0, or beta, but since when did that mean it should be slow as a slug? I think Apple needs to focus on releasing faster software (including its OS). It's ridiculous for anything to be so slow on such a "fast" machine, especially when the PC world is putting out machines that are much faster these days.
It is the Mac's beauty, ease of use, originality, high-quality design and manufacturing, and stability that attracted me. I am being patient with Apple and riding the bleeding edge with them, but I hope they speed up both their software and hardware soon.