Mine seems about the same. I just love the fact that a single click takes you back to the home screen, click again and it takes you to spotlight. Then I have double click set to the camera. I love this new phone.
Shortly after I purchased my 3G last year I had to replace it with Apple do to a malfunction, the replacement phone they gave me was considerably more stiffer on the home button than my original one was. There's no real "click" like there is on my wife's 3G.
Just to provide follow up to my own message, I got my phone replaced today. I think that there may be some misunderstanding of the symptom, at least what I experienced. On my defective phone, the button was stiff and did not have a distinct click. The lower part of the button could not be pressed in as far as the upper part of the button, and it did not respond to pressing on the lower half.
On my replacement phone, the home button is stiffer than my 2g and 3g, but it travels straight down and with a nice clicky feel. Pressing the upper half or lower half feels the same. This matches the other 3gs models that I have seen.