Hi. I am a At&t customer and I want to get the Samsung Galaxy S2. However, I like how the international version has a physical button as opposed to how the At&t version does not. Therefore, I have a few questions that I would really like to get answered from you guys 
1. What are the pros/cons of using the international (GT-i9100) version rather than the original At&t version?
2. Are their specs/performance equally the same?
3. Can I use the 4G internet the International version has with At&t network?
4. How come the international version costs $100 more than the At&t version if they are technically the "same" phone?
Thanks a whole lot guys!

1. What are the pros/cons of using the international (GT-i9100) version rather than the original At&t version?
2. Are their specs/performance equally the same?
3. Can I use the 4G internet the International version has with At&t network?
4. How come the international version costs $100 more than the At&t version if they are technically the "same" phone?
Thanks a whole lot guys!