Spade vs. banana plug

In my mind I always thought banana was a more direct electron flow into the XO, but 2 reliable sources say spades are better

I don't have a preference in terms of the effect on the sound but do prefer the Z-plug or BFA style banana connectors. They provide a large contact area and the ability to slightly alter the diameter to fit what are often slightly inconsistent sizes in the diameter of the holes in the binding posts across brands.
LIke this -- https://bit.ly/3kam3Ct

I found that spades tend to get loss over time. A good tighten is required here and there. Banana plugs, especially the spring type, never get loss.
So, since I use only banana plugs.

Spade, banana, unterminated.  

Paper, rock, scissors.  

Read, set, Go!

Depends on if you want best sound over the long haul - low mass, gas tight spades give you that.