I did SMDEP a few years ago. The purpose of this program is to expose underrepresented minorities in medicine/dentistry to the field, so being an underrepresented minority is one of the most critical factors in being accepted- more important than GPA I think. I would say it's not too difficult to get accepted based on people who I know who got accepted.
Overall, I had a good experience at SMDEP. It was fun living in a new city for the summer. I met so many friends who I still keep in touch with. We got mentors at my program site, and I still talk to mine from time to time- I asked them a lot of questions when I was studying for my DAT and applying to schools. You take classes, attend seminars, and get clinical shadowing experience once a week in different departments. Each program has its own schedule- some programs have more clinical shadowing than others while some focus on classes/academic preparation.
One thing I reallyyy didn't enjoy was taking classes every day though. I did the program after my sophomore year and I had already taken all of the classes they made us take (physics, ochem, biochem, genetics), so the classes weren't beneficial for me.
I definitely recommend the program though. Everything is paid for (travel expenses, food, housing) AND you get a stipend. Plus, it looks great on your application and you can talk about it a lot during interviews. So why not? 🙂