I just returned from a week on the Celebrity Summit. For what it's worth, this review will probably only be helpful to those sailing Summit for the next couple months because after January, she will be totally refurbished.
Embarkation - It is what it is. Like most services in Puerto Rico, embarkation is not a well thought out process. If you show up prior to the ship being opened, you are made to wait outside without any seating. From there, you check-in, then make your way up 4 stories to the ship. Do not carry anything heavy because the escalators were broken. The broken escalators are an important thing to remember if you plan on doing self-disembarkation, carrying off your luggage, at the end of the cruise. The whole terminal is old and is falling apart. Boarding began at 11:30.
Despite the ship scheduled to sail at 8:00pm, all aboard was 4:45.