So I went out and saw it. Might as well give my review for others with the same question.
Quick summary: American girl gets a job to deliver something in Ireland. She gets lost in a forest where she finds a small group trapped there by the Watchers, for a name that makes sense.
I thought it was not as bad as I thought it was going to be for the bad critic scores and mediocre audience scores, which have been in like the high 30's to 60's in % review sites. But then, I don't see a lot of movies nowadays, so my bar may be lower than other movie buffs. It definitely has a lot of the feel of a Shyamalan movie even though it's his daughter directing. It's got the trademark suspense, thriller feels, and some horror and dark fantasy and on the nose themes. Don't worry if you're averse to horror, as it got nerve-wracking but never crossed into horror levels of scary imo. Still, atmosphere has always been her father's strong point, and she's managed to keep that going, which is good.
Dakota Fanning did a good job acting with what she had, but it wasn't a lot. All the characters felt kind of thin and paper, as they skipped most character development to get right into the premise and mystery. At least I think so, we arrived to the theater a bit late lol. The characters basically give you enough to justify their actions by their personality and that's mostly it. It's not as bad as like Avatar or The Happening, but the characters didn't feel as real to me as let's say Sixth Sense or Signs (to compare to other movies from the family name). This does slightly benefit the movie in some places, because the weird characters with little history adds to the slight atmosphere of distrust between these characters that are thrown together.
The end probably could've been slightly better, but I didn't think it was as bad as other reviewers felt. It did the job, made sense enough to wrap up things, and I was ready to leave by then anyway.
Overall, it kept me mostly entertained for the time I was there. It had enough horror to add some suspense, without actually being too scary so my family could watch it (my grandma and small children probably would've been too scared to watch it, though). It needs something to push it into the next tier, but I'm not sure what. Maybe it needed to be scarier, or more action, or something. Still, not bad for a first directorial outing, it just didn't blow me away.
Final note, I haven't read the book, so I don't know how accurate this is to it. This wasn't quite memorable enough to convince me to read the book, but it was an entertaining enough plot that I could see why it was made into a movie.
I'd give it a 7/10.