Papas,
I use the DAPS as opposed to Jepps...to be honest,its better to stick with what you know for IREX. Neither is better than the other (except, perhaps, that Jepps charts are made of some VERY thin paper and prone to tear when doing ATPL Nav).
Good luck on the IREX...my advice? Read the question (carefully) then all the answers before selecting the correct answer...she's a tricky one the IREX.
Luck,
HP