iPhone 4 is the best phone I've ever had. I am very, very happy with this purchase. It's factory unlocked, so I am using it in Venezuela with Movistar, and I have all the iPhone services active
Pros:
1. Great design
2. Very good quality images and video (from main camera, and not so bad from the front one)
3. Great sound (with and without headphones)
4. The best screen you'll gonna find. Bright colors, best resolution
5. Thousands of applications
6. If you have an iPad and/or a Mac this phone is the best choice to keep all your data synchronized, and a full wireless access
Cons:
1. Firsts days, the battery life was a bad issue, but then I found that there is a service called "ping" that you can unactivate, and the battery life increased 90% (some days I even don't charge my phone overnight, and next day I still have 60% of battery)
2. High price, but it worth it
3. Sometimes I wish it would have a full qwerty keyboard, but right now I feel very comfortable with virtual keyboard
Important: There is no "antenna gate" issue with my phone