Garrison Fox’s review published on Letterboxd:
Philomena is a pretty low-key film. The score is quiet, the photography is fairly plain, and the writing is straightforward. Typically, this subtlety is perfectly welcome, but the humor is so subtle that it isn't terribly funny, and the drama is so delicately handled that it isn't terribly affecting. Instead, Stephen Frears' film is a bit sentimental, though not excessively so, and a bit plodding, though not meandering. Where the film shines is in its performances: Judi Dench understatedly portrays the sweet, naive, unintentionally amusing Philomena Lee, and Steve Coogan portrays journalist Martin Sixsmith with his usual sardonic wit. Unfortunately, their performances don't make up for the undemanding script. The film attempts to end the story on a lighthearted note, invoking a moral lesson to essentially gloss over the Catholic Church's past misdeeds. That's not to say it implies that what the Church did was permissible, but that nothing can and/or should be done about it.
Aside from those quibbles, Philomena really isn't a bad film. Actually, it's quite charming, and when I say it isn't terribly funny, I still find it entertaining; I even recommend it. The film just treats the root of the problem with kid gloves, debasing its purpose.