How often do you use the following words?
so much so that
These words magnify or emphasize the words around them, but they do so in a trite and meaningless way.
Bob was so beautiful that the girls couldn't get enough of him.
Kathy was such a beautiful girl.
Neither of these sentences say anything. They tell--they don't show. Worse, they tell forgettably. Bob may be beautiful, but how? And why? What exactly is beautiful about him? You haven't revealed a single detail about Bob, and therefore the reader cannot possibly understand or imagine him.
Two more examples:
It was a hard exam, so much so that no one passed.
The exam was so hard that no one passed.
How was the exam hard? Why was it hard? How do you feel about how hard the exam was? Neither sentence offers the reader a clue about these important details.
Avoid these words like the plague. They signal a lazy and unimaginative mind. Give a better explanation. Make it more real. Make it more memorable.
PS: I'm guilty of using these words too (but please, no comments about my lazy and unimaginative mind). In fact, if I could ask my readers a favor, I'd be grateful if you would call me out any time you see me use a vague modifier. Here's to hoping you can help me break my own bad writing habits.