I was part of Project Healthcare, which runs during the summer at Bellevue. PAVERS runs during the rest of the year. I was not part of PAVERS because I took classes outside of the city.
Project Healthcare is one of the most amazing experiences one can possibly have during his/her pre-med years. Although it's only 5hrs/day during the summer, the commitment is pretty demanding because you are randomly assigned morning/afternoon/night shifts throughout the week (including weekends). It requires a lot of maturity and goofing around is not tolerated.
As a "red shirt" (as you will be called because of your red polos), you will rotate through the various departments in the ED. That includes Adult Emergency, Peds Emergency, Psych, Discharge, Social Work, Research, Recovery Room, etc. You will communicate with patients, fetch them food/drinks/blankets, make stretchers, transport patients on stretchers, perform EKGs and, on occasion, be asked to assist a nurse, resident or attending on a procedure. I've volunteered at 3 hospitals and it's rare to be given this level of patient access.
Project Healthcare has certain privileges that PAVERS do not have (I was not part of PAVERS, so perhaps I am wrong about this). One is being able to follow trauma patients (car accidents, gun shot victims, etc.) into the slot and observe the nurses and doctors do their thing. On rare occasions, you may be asked to perform CPR on the victim (you get CPR certified). The second is the coveted OR shift, where you gown up, walk in on operations and observe procedures literally 3 feet away. Many times, the surgeons are friendly enough to discuss what they are doing with you.
Needless to say, I am a fan. If you have the time and are part of the lucky batch of folks who get selected (it's pretty competitive), it's almost certain that this will end up as one of your "most significant experiences" on your AMCAS app. Let me know if you have any other questions about Project Healthcare. There are other aspects of it that I haven't discuss (ambulance ride, autopsy, health fair, research project). Feel free to PM me if you want to discuss anything off the public boards.