i will have to give a more round about answer as i could write on and on for something way too long in a post, in the future it is something i will be writing about in more depth as this question has come up many times before.
i will give a quick synopsis of the differences though. overall, they are both very similar proteins, yes they are both naturally consisting of 80% casein and 20% whey, but the CMDI goes a bit further. it is processed in a much less harsh environment which yields a much less "processed" and undenatured protein powder. this gentler processed CMDI retains many of it's natural protein fractions and subfractions.
many of you may have been hearing of these as of late, they are the lactoferrin's, the immunoglobulins, etc. they may not seem like a big deal but these fractions and components that are often left out of many protein powders have a wide variety of uses. lactoferrin in particular has many protective values of the immune system (anti-inflamatory, anti-microbial, anti-viral, anti-tumor), studies have even shown inhibitory effects against HIV and cancer. and with most of us training heavy, the extra effects of cortisol blocking and added growth factors are always a plus.