A beautiful structure and very "green". We took the free tour that is offered at 1:00 on weekdays and discovered so many interesting facts about the building such as it being lit only by natural light during the day and there being no need for AC or heat most days due to aspects of construction that save energy. They also explained how it is kept safe from earthquake damage despite being encased in glass. The blending of glass and wood was beautiful. There is also some 16th century art incorporated into this very modern design. Don't forget to visit the crypts in the lower level.
As a worship space It was better than I expected. We attended a weekday Mass and it was not cold and impersonal but warm and inviting. Easy to get to on the BART. The cafe and gift shop adjacent to the cathedral were nice too.