For those who have both the PMP and the CISSP certifications (Certified Information Security Systems Professional), which do you think was the most difficult? I ask because I am CISSP certified and first time passer of that 300 question exam. The PMP and the CISSP are approximately the same level of certification within their respective domains and I would like to get an idea of comparitive difficulty. Obviously they don't cover the same topics, so your knowledge in each domain is a factor, but over all what are your opinions?