These were really good and very easy to make. I had no problem with them setting up or the chocolate. I will say one thing, for those who don't bake that often. I often make things coated in chocolate. In the winter months, they set up within an hour and they set up beautifully. However...during the summer months, I find that the chocolate needs to be allowed to set up for 24 hours. So, if done during the summer, make them 24 hours before you need them and you should be fine. But they are great.
I liked these, they tasted similar to reeses cups. I used natural peanut butter, they were easy to shape, and were not to sticky. I would make these again, but instead of using semi- sweet chocolate I would use milk chocolate. I melted the chocolate in the microwave with some oil like others suggested and it turned out great. I made my balls quite small, (about 1/2 golf ball but bigger then a marble) and the ratio of chocolate to insides seemed good.
Made these for my family for christmas. She also got a set of box chocolates, with the same sort of idea. I was kind of worried but she liked mine so much, she said she'd trade the whole store bought box for just one of mine! I used milk chocolate chips, semisweet baking squares and vegetable oil for the drizzle.