Flexibility. Do you ever plan to own a .300Blk? Do you ever plan to hunt with say a .308 or even 6.5 Grendel or Creedmore? It's just a no brainer in that for a little bit more money up front, you wouldn't be limited so very much on caliber selection. It's all well and good if you can afford both 5.56 and 7.62 cans but can you?