I was so super psyched from this and came away thinking that it was good but not great. Not really worthy of all the heaping praise.
Certainly I admire the ambition of the film, and RL's ability to finance it and pull it off as a coherent story is an immense success in and of itself.
However, I thought some of the acting from and writing surrounding the stepdad characters was pretty weak. Like I felt like I was in an after school special. Also, didn't think that Arquette really did a great job as the single mom. She brought it in some scenes, but felt sort of cardboard in others.
The scenes with Hawke and Coltrane were the best for me. Wish they had explored that a little more. The sister, Linklater's kid, was also pretty great. Sort of reminds me of a young Maggie Gyllenhaal. She has a bright future.
For me, the last half of the movie was way more interesting than the first half. I would much rather see age 10-22 than 6-18.
Also, dont really think it is a 'monumental shift in the way movies are made' since I dont think that in today's environment that it will be extremely difficult to fund projects like these. Linklater did an interview for grantland talking about his relationship with IFC and how lucky he was to keep funding for the movie over the years.