It's a pretty hardcore program. From what my classmates who have doen it told me, you study a lot and take a lot of classes at the same time. Imagine going through dental school didactics for 3 years instead of two, and that may be what it is like.
It is very competitive and you must test into the program. Based on your scores, you will be placed in either the 2+3, 3+3, or 4+3 program tracks. The major problem with the 2+ and 3+ tracks is they are especially geared to Pacific, and it doesn't guarantee acceptance. you must perform well and also do well on the DATs to get into Pacific. If not, you are often screwed out since most other schools won't take your 2 year program as enough for them to accept you, so you end up waiting another year to apply anyways.