"This is so grammatically correct that it's stylistically incorrect." That's a comment from my son John about this:

"One of the things that have most impressed me reading a file is..."

He adds:

It reminded me of an example that my linguistics prof showed the class. It was something like this: "The dog the girl the boy saw chased ran away." It's possible to logically explain that the sentence is grammatically impeccable. But it's still an obviously unacceptable sentence. This example was a minor revelation for me.