Here is a comparison between a couple of iPhone 3G's we had at our office. One upgraded to 4.0 and the other is still on 3.1.3. This is actually the fastest the 3G with 4.0 has been, it used to be slower without the double hard reset and reset all settings! I hope someone at Apple will realize the slowness most of us are feeling and find the cause, and of course fix it.
