I switched from a Droid X to an iPhone 4 over three years ago. I still have the iPhone 4 and its only issue is that the lock button sticks.

With that said, I loved the droid ... it just wasn't reliable. It would constantly reset/screw up/delete things and became a total headache. My iPhone has been rock solid. I'm due for an upgrade, and I think I'll stick with the iPhone, but the samsung phones are pretty. I just don't need a mini tablet-phone, I already have an ipad. That and I'll be entering medical school next year (hopefully), and 99.99% of US medical schools roll with the iOS platform.