Front row reviews has posted an in depth review of Side by SIde. Ollie Charles does a good job of covering the arguments. He also gives a shoutout to the geeks who are really into the subject matter.
He ends the piece saying:
Side By Side is one of the most interestingly bold, unique and fulfilling documentaries I have ever seen. It made me truly understand some of the biggest issues in cinema today and brought me closer to some of the most genius filmmakers currently working. I would certainly recommend to cinephiles and cinemagoers alike.
The piece can be read here.