I enjoyed season 1-3. I enjoyed watching the characters development. But then Jim died in season 4 and reincarnated again as Sam and it got really confusing. I didn't really enjoy that twist. I was kind of hoping that they would kill off Jim/Sam entirely midway season 4.
Overall I really enjoyed the message and all but yea it was just the Jim/Sam story that bugged me a little. And also Professor Rick Payne. His last episode also really bugged me.