I'm a nova OD1 and Im friends with several of the people who made it through last years POP program. Yes, it's an extra year and the stress of "not making it through" it tough, but if you make all A's through POP, OD1 year is a breeze since you don't have to repeat A LOT of the classes and your course load is way lighter. If you get a B in POP year, you have to repeat it, but you will have notes and remember how the course is taught, etc. if you get a C, you're in trouble, I'm not sure how this works.
The downside to this is that I hear that OD2 year is the worst, and after 2 years of a "light" schedule, the transition to a killer schedule might suck. But it's a good program nonetheless. 3 girls were our anatomy TAs and were POP students last year. They made a killing on private tutoring and group study sessions. Plus Nova is a great school, underrated, and if this is your shot to get in, go for it.