i work with insights too, for the second year; what i can say about it is that the book has its ups and downs:it is full of mistakes , too many activities, redundently boring activities; misplaced activities(reported speech/inf & gerund)modals and ..........
yet the book has its good sights ,i personally believe that if it were covered students will find no problem while sitting for their exams, just do a little efforts to make things better,and it will work better.