Ran this past my D, who did info sessions for admissions when a student at Cornell. She said that California is the third most represented state (behind NY & NJ) at Cornell. In addition they have a 97% fresh-to-soph retention rate which puts them just out of the top 10 of all colleges for that stat. Logically the boost that applying ED will give you appears worth it, weighed against than the relatively small chance that you will not like it there.