A few reasons..
The biggest factor was cost. Both are private schools, but NEWENCO is more expensive. Plus the cost of living in Boston is much more than suburban philly.
The exam rooms and equipment at PCO are more modern and newer, compared to NEWENCO. I've heard a few other people say this too.
By the time we graduate (with this new curriculum), we will have seen 50% more patients than other optometry programs and this was the second biggest factor for me.
Another reason i chose PCO was the closer proximity to ny (1-1 1/2 hours) compared to Boston (3-4 1/2 hours).
They are both excellent schools, and it was one of the toughest decisions i had to make, but in my heart i knew PCO was right for me.
Good luck in your decision!