The Goat is the smallest pup, by quite a bit.  I don't think this will have anything to do with eventual size, considering that Brutus was the biggest pup in his litter for a long time and now is somewhere in the middle size wise.  GTO is amazing, though.  He's walking today, the others are not.  By walking, I mean up on four feet, nothing dragging.  He's also making barking type sounds.  Pushing air through his voice-box instead of whining.  He's an early favorite around here.

You can already see the blaze on his face is shrinking and becoming more defined.