I enjoyed it quite a bit. Full on nostalgia, but still brings in new characters, and the kid actors were all great.
It's directed by Jason Reitman, who is the son of Ivan Reitman, who helmed the 1984 and 1989 Ghostbusters (as well as Stripes), and I really liked how he handled things. Similar score as the original, heavy use of practical effects, good humor, great photography, etc. Outside of "Ray's Occult" bookstore, they basically ignore the events of the '89 sequel (which is good, IMO, tho I still like that movie). And I think they handled the absence of Harold Ramis (died in 2014 from cancer) pretty well.