Great question. I know some CMers who have used and loved those resources and others who have not enjoyed them as much. I'm happy to give my personal experience here, but please remember that you should feel free to use what will work best for your family.
When my girls and I started Simply Grammar (which is a revised and expanded version of Charlotte's lessons), we found some of the terms different from those I had been taught and used. We also found parts of it a bit confusing without an answer key to help us discover what we were misunderstanding. Add to that the fact that I wanted my children to learn how to diagram, which isn't included in Simply Grammar, and you can see why it wasn't a good fit for us.
Elementary Geography is a wonderful book, but since I try to combine all my grades for geography I thought it a bit young for that purpose. Also, I try to focus on one continent each year, so the ideas in Elementary Geography don't quite fit with my overall selected plan.
That being said, please use them if you think they will work well for you and your students. I just don't recommend them because I didn't use/finish them personally.