I believe there is a word limit (50 words) for the notes page of the PPT. They want each slide to stand for itself as much as possible. With that being said, there is no word limit to the text on the slides. However, I do not think that the purpose of PPT is to slap a ton of words in a text box on a pretty background. If that is what you're going do than you're better off just writing the essay. I've seen quite a few PPTs from my peers and while some had more text than others I do not recall any with 750 across the four pages. The point of this essay is to show your personality not just in terms of the content but also in the way you present that content. If I was a 2nd year on the adcom and saw that many words in the 4 pages I would think that the applicant is boring, lacks creativity, and more importantly isn't even willing to try to go outside of their comfort zone. Considering the fact that a large part of Booth's culture is about challenging oneself this is not a good perception to leave with the adcom.