I disliked the ending. OMG HIS HEART DOESN'T WORK! OMG! I WILL GIVE HIM MINE!!!
So many things wrong with it, especially after Marcus displayed how badass he was and how kickass he would be as an ally. I did enjoy the Arnold-like cameo. The fight between John and the T-800 was nicely done to acknowledge the fight from the first two. I also liked how it kindof ignored the third film, though I don't know if that was intentional. If anything, I hated how John and his wife/squeeze were supposedly in their 40's (2018, with John being a little kid in the 90s) yet both looked like late 20s early 30s even after two+ decades of a war.
The most interesting characters were the pilot and Marcus. I really wish he'd survived to continue the franchise. What would really have been interesting would have been if he sired a child.