The phrase "middling reviews" means a mix of good and bad reviews or ratings. It suggests that something or someone received average or mediocre feedback, not overwhelmingly positive or negative. Full definition
Produced by friend and mentor Louis Malle, Cavalier's metamorphosing tale of obsession and repression was originally met with middling reviews in l'hexagon upon its release in 1962. (contactmusic.com)
It's only fitting that Kubrick be associated with this film since A.I., like Kubrick's finest works, is one of those films that will received middling reviews upon release only to be considered a classic film by future generations. (qwipster.net)
The Darkest Hour earned itself a Best Picture spot, despite middling reviews overall, and Phantom Thread made a bigger showing than expected, earning nominations of some of the biggest categories, including Best Picture. (theyoungfolks.com)