I've never seen it before, but I've been using the M1 0w20 AFE for awhile now, and I am very please with it.
I'm guessing the EP has a more stout additive package. but If your doing less than 10K OCI's, the M-1 0w20 AFE should do you fine. My last OCI was 9,200 with a Fram Ultra filter.
Yeah its about time, but honestly most who do 10k+ OCI's with M1 AFE 0w20 seem to come back with great results.. So I would only consider if I decided to run such an interval.. (doubtful)