>> "In particular, I found the required casting of AnyObject! to whatever I was expecting it to be not perfect (sometimes I thought that the typechecker really ought to figure some types out). Also, best practices for when to use NSArray vs. Array / NSString vs. String, etc. is another thing I look forward to."

Same issues I was having. I was porting an obj-c class to Swift and continued to use obj-c objects (NSString etc.). I then had to put 'as NSString' at the end of most lines. I'm considering going back and experimenting to see where I can use swift native objects. Hopefully this book will shed more light on the subject.