While Call of Ctulhu was the best of Metallica's instrumentals I like Orion more. Especially the 3/4 tempo middle part. I didn't know the riff played at 0:52 was originally played on the bass. Considering Cliffs influence on the band at the time it makes sense though. I learned something.
Cliff Burton not dying and having remained a creative influence on the band is probably one of the great musical what ifs, as he seems to have been the driving force behind their prog era. And without him it just didn't come together on In Justice For All, causing the band to go simpler subsequently. I don't think we would have had that era if Cliff had been around. No offense to Jason, who was a perfectly good bass player, but him getting shafted by the band meant he could not really step into Cliff's shoes. He just wasn't allowed too.