Personally, I feel that it doesn't matter where you go. The most important thing is your attitude. If you surround yourself with American culture, you can definitely learn a lot in a short period of time. Learning American English is not just learning the vocabularies and grammers, but most importantly understanding the culture. A language is evolved around the culture it serves. So prepare yourself for culture shock and have a lot of fun. And most importantly, be safe. Just to remind you to be aware of the race issue if you decide to go the mid-west.