I highly recommend the i-75 courses! Darius does such an excellent job teaching the material with great examples that you truly understand the topic. It is like you are in an actual classroom. I originally used Wiley and some of the instructors were so hard to follow but I did not have the same issues with Darius’s lectures… stuff actually made sense.
Anyone struggling with the concepts should try i-75 without hesitation and you will be glad that you did.