well, I saw it because I hoped it would have some insights about A.I, but I was

the characters had no emotional depth and didn't really go threw any growth process.
the t800 was reduced to a beta provider for a single mom.

they didn't expand at all on the rev9 ability to duplicate :

how do they work together, do they communicate with one another, how do they
strategize, what is his priority to reform vs to attack.

also the ease by which they killed john was unlogical.
and what were they fighting for ? what was the motivation and back story of legion ?
the reasoning why t800 refused to work with rev9 didn't make any sense :
because he failed in the past ?!

the only rediming of the movie was the action and explosions, tho it was to one sided
so it wasn't that good, it was more of a Friday the 13th movie than scifi.