For people upset that it didn't stay a duo-logy anymore, it was never planned as such. Patrick Wilson being in the Conjuring is why he wasn't present in Insidious 3 or 4. I was happy to see all the original cast in this film. People complain about the pacing, I do not see anything wrong with it. Its a really great movie, for closure on the first 2.
If I was to complain about anything in the movie without spoilers, it would be they didn't touch on the divorce at all, they also didn't focus on if the end, was the end of the demon. They also could have fleshed out the father more of the actor Patrick Wilsons character.
I think old fans of series do not like the college approach setting, and new fans do. Either way I don't think its bad in any form. I think leaving so many doors open, lets them make another movie if they want to.
I think for the order of this series I would go 2,1,4,5 and 3 is my least favorite entry. But watching these in an order I did 1,2,5,4,3. With watching with a group. 1,2,5 were praised the most with 4 being great on its own, and 3 feeling the furthest from the series, and least scary.
Thats my opinion,
Great Job Partrick Wilson, Loved It!