I found those to be interesting and informative, but merely covering 1 relatively watered down topic in my grad/med level coursework. Its certainly not a bad thing to do for learning some new. But its also not something epic. Remember the interviewer's interview you, so they may ask you about something else unrelated to taking a brief "mini med school course".
I took a mini-med school course on regenerative medicine at UCSF ages ago. But I don't think basing my desire to be a physician on attending a mini med school course would be a strong statement and not all that impressive compared to say... taking a real med school course.
But yea, its not a bad thing. Go ahead and do it, but do it because you're going to learn something. This concept of doing something to pimp out your AMCAS is naive. There are people out there with some amazing applications. The best thing to do is to do something that you like so you can excel at it. Just like research, if you know your research well, then if asked during interviews you can talk about every aspect of it. That is impressive, rather than just "i did research for 3 months".