The best part of Issues and Science for my students is the storyline that goes along with each unit. Lessons are well laid out and easy to understand. Student work is completed mainly in pairs or groups of 4. It's very hands-on with coordinating worksheets that can be kept in students' science notebooks. The lessons and coordinating Power Points allow me to stay target with NGSS. I also love LABsent - the provided tool for teachers to give to absent students.
The biggest shift in teaching and student learning is that the students now follow the same/similar format each day learning (just with new activities and content).