I switched from the BB Tour to the iPhone 4...and then to the 4s due to the 4 being damaged in a car accident. The switch to the 4 and transition to the 4s was the same. If you're wondering about the opinions...other than the time it took to get used to losing BB Messenger (iPhone 4s has the iMessage feature so it's kind of the same...only for iOS users instead of BB users) and the better handling of emails that have to be fetched (they are a bit slower depending on the fetch interval you use) I am happy with the switch. Note that emails from other sources tend to actually push instantly (the free email you can make for the iPhone for example will push immediately). I definitely don't miss the battery pulls I had to do on an increasing rate on the BB and the internet experience is much faster and better....at least it is to me. There are other things that are better to me personally, but those are some of the top ones that pop into mind.