It just gets bogged down easier now. Some apps won't even show the launch animation correctly. Playing music though the dock connector while you're using it makes it run slower than heck. It performed much better for me in 2.x.
So you and your friends don't notice that and that's fine, but I can't live with that kind of perfomance, so I'm upgrading to the 3rd gen iPod touch. I can't wait!!!
Sounds like your iPhone was pumped, rather than 3.0 bogging it down.
I've uses numerous friends and family members 3G's running 3.0 and have played around with the 3.0 enabled iPhone 3G's in the Apple Store here in Glasgow and all of them run absolutely fine.
Yes, it is slower than the 3GS by a few milliseconds here and there, but I've never once seen app launch animations go missing or felt the handset was acting like it was "bogged down".
I can understand and appreciate your reasons, but the iPhone 3G has not become a piece of **** overnight.
Sorry.