Oh, just another feedback from my PI. I sent my personal statement to my PI and after he read it, he told me just leave it as it do not cut it down. My PS is about 1000 words, he said a good 1000 word PS is totally fine for the committee members. He also said :"I am only aware of length when an essay is difficult to read." So if you are confident about your long PS, dont worry about it. This is just an advice from my PI.
PS. My PI was the DEAN of Columbia school of Physician and Surgeon, and was one of the committee members who to review and interview students. I will totally trust his words.