Granted, I'm saying this as someone who hasnt made it out to Haunt yet this year, so just going off past experience. But I personally don't really go to GrimmWoods for scares. I go to it simply for the vibe. It's very unique at Haunt and really crushes the Halloween spooky vibes. I walked through by myself last year with no groups ahead of or behind me (right before closing) and I had a blast just taking my time and taking in the scenery. I mostly never get scares here, but for me, it's just all about feeling that spookiness and unease while walking through the woods. To me, GrimmWoods nails the feeling of Halloween better than any other area of the park (which the park is generally very good about), aside from maybe Pumpkin Eater.
It's become arguably my favorite part of Haunt on vibes alone, though I can understand if that's not for everyone.