Here we go! The review embargo has been lifted.
Some people were wondering if the overwhelmingly positive reviews were due to Neon's select screenings to more generous/favorable critics (horror and genre enthusiasts). Well the floodgates are opening now, it's holding up pretty well though of course it's lost it's 100% score.
RottenTomatoes - 91% (129 reviews) [Top critics - 91%, 33 reviews]
Metascore - 78 (44 reviews)
Avg score on RT - 7.70
Avg score on RT amongst top critics - 7.80
https://www.rottentomatoes.com/m/longlegs
https://www.metacritic.com/movie/longlegs/