I'm in the same boat. My GRE score is about 50%, which is way below what I've expected. I think it depends on the schools you are applying to and your whole application package. I talked to a professor in grad school during my summer research, and he told me they would prefer to see the score, even though it's just a mediocre one (their program recommend subject GRE).
But I'm still hesitating to send my scores to several prestigious programs (Berkeley, UW).