There are quite a few useful old threads with information that can help you. Try typing Égoïste Cologne Concentree in the search function here, there should be some old threads comparing the CC to regular Égoïste. Make sure you use the Égoïste and not Egoiste.
From what I have read/been told, the CC has more sandalwood, less vanilla. I decided to go with the EdT, because I preferred the extra vanilla.