My basic take is the same as for Fury Road: if I were an action movie fan, it would not be possible for a movie to target me more forcefully and specifically than this. I'm not an action movie fan, so there are sections where my reaction is, "Ho hum, can we get past the speeding around and blowing stuff up part and back to the interpersonal interactions part?" Ghostbusters had a bit higher people-to-explosions ratio than Fury Road, but they were both exellent in their own ways.
I'll leave off reviewing the premise, which is inherently goofy and doesn't stand anything in the way of scrutiny. The four principal actresses have outstanding chemistry and all play clearly distinct types without ever being reducd to sterotypes. Leslie Jones's Patty nails the type of local-history-geek who makes for great exposition. Kristen Wiig handles the initially-uptight academic, but redeems the character by the grace with which she's recalled to her original wonder and curiosity. Melissa McCarthy's character covers the combination of no-nonsense drive and tinfoil-hat focus needed to pull together a team of this sort. But it may come as no surprise that my heart belongs to Kate McKinnon's Holzmann--the archetypal mad scientist who mixes in the ass-kicking skills of an action hero.
It is evidently an open secret that Holzmann was supposed to be canonically lesbian. A few traces remain (like greeting Wiig's character with "Come here often?") but it would have been nice to have it confirmed in script by something more than innuendo. Definitely an icon for the ages!
The casting of Chris Hemsworth as the ditzy airheaded eye-candy secretary was a piece of genius. And the role is such over-the-top satire that I think reactions to the character can validly be used as a litmus test for sense of humor. The many call-backs to the original movie and cameos also add to the message that the movie is meant to be just plain fun. (I'm sure a lot of the cameos passed me by, due to the whole "somewhat face-blind" thing. But I did spot Murray and Aykroyd with no problem.)
I don't know that I'll be a repeat watcher of this movie, mostly because of the whole "not really my genre" thing. But it was a great way to spend a hot summer afternoon with the BFF.