Hi Renaud,
I have taken courses with Sophia as well as Study.Com. I think it depends on your studying style. Sophia has different teachers with their own methods and style of the material given. Seeing a different perspective on a subject can be very helpful. I found Study. com is a program that is very straightforward. The practice tests for each lesson as well as the chapter finals are very helpful to study for the final exam. They both have their strengths and weaknesses as any program does. Due to my work schedule, i liked Study.com because I am able to print up the note cards at the end of the course to go over the important points before testing. I would like to hear what your take is on this so hope to hear from you soon. If you have any questions on courses, please feel free to ask since i have takes such diverse subjects while in the program. Krysteen