Best explanation I've seen so far for Hemi cam/lifter failures

Just saw a guy on ebay selling the real Mopar Lifters made in Germany for 649, right under people selling lifters, cam, oil pump, timing chain set, full gasket set, water pump for between 396 and 738.

The interesting part is him saying that the MDS lifters are 2 solid roller lifters and 2 MDS lifters, so 2 are solid and 2 are hydraulic. That would be the MDS delete lifters are all Solid roller lifters.