It's interesting that you say that because I have the exact opposite experience: I've been an iPhone user since the day after the first generation came out and

It's interesting that you say that because I have the exact opposite experience: I've been an iPhone user since the day after the first generation came out and after I got a 3G, I noticed that it would slow down sometimes, scrolling was a pain (the scrolling itself was quick, but when it finished the scroll filling in the newly-invalidated area took forever), voice calls dropped, the physical case was falling apart (mostly because I bought it used that way), and I really disliked switching apps so often. When I got my Nexus One with Froyo, almost all of that went away: scrolling is immediate and smooth, voice calls sound much better (and I'm on AT&T!), the case is much more solid and not splitting, switching between apps is much smoother (I don't know how I lived without the "universal back button"), GMail/Calendar integration, etc. Oh, and the day I received it in the mail I plugged it into my (Ubuntu) laptop and created a camera app that takes pictures using the volume buttons on the side, uploaded it to my phone, and use it all the time.