I used it prior to destroyer (currently doing destroyer)... It's essentially just like the orgo section of destroyer except for every 1 orgo question in destroyer, there are 10 in odyssey (and they are organized into sections)... I went through the orgo section of destroyer once... it took me under 2 hours to answer all 200 questions... I got ~85% correct and the majority of those I missed were just stupid mistakes in questions that I knew how to do... Maybe 5% of the questions I actually didn't know the answer to after doing odyssey. Considering how I remembered nothing prior to doing odyssey, I'll take that. On the other hand, since people say destroyer is overkill...