Original or cover version?

In 1970, the group Rare Earth scored a #7 smash hit with "(I Know) I'm Losing You".  Just three years earlier, the Temptations had reached #8 on the same Hot 100 with the same song.  The song was also covered by Rod Stewart and Faces, the Jackson 5, and several others.  Personally, I much prefer the Rare Earth version, although each is very good... the sad part is that the Rare Earth version has become a forgotten oldie.