Bananas rule, spades drool. End of discussion.

If you biwire with two separate identical cables, which is the recommendation,  and you only have one pair of speaker outputs on your amp, well then you have no choice but to use spades on one of the pairs (amp end). 

I’ll chime in with a comment on this topic.  I had spades for many years and I think one of the two cables would come loose and drop off every couple of years.  It didn’t occur to me that I could use channel locks to tighten them so they wouldn’t fall off.  Finally I discovered that there are different sizes for spades!  At that point I examined mine and they were clearly too big for my binding posts.  That was clearly the reason they would fall off.  So I finally switched to locking bananas.  That brought up another problem.  For some reason I struggle to open them and I’ve actually come to dislike them.  I’ve read that regular bananas  can loosen but I have them on my electrostatic speakers and they’ve never seemed loose.  And I’ve had the same bananas for decades.  So I prefer regular bananas.

I’ve had trouble with spades coming loose.  I finally learned to use channel locks on them.  More recently I discovered that there are different sizes of spades!  I learned that mine are way too big for my binding posts.  The spade prongs are too wide apart and the binding posts barely  grab them.  I finally switched to bananas and thinking locking bananas bananas were superior to bananas, I chose the locking sorts.  I have come to dislike them because I struggle to loosen them when needed.  Just last weekend I had to wait for a male visitor that I could ask to loosen locking bananas for me..  I had been given an Audio Video Receiver and the male who gave it to me tightened the locking bananas.  The binding posts are so close together I couldn’t get a good grip on them nor would the channel locks fit in either so I was really stuck.  It’s actually a challenge to find regular bananas on speaker cables.

Having to use channel locks kind of proves my point.  I mean, sure use them if you want to, but knowing you must use them because the spades will otherwise come loose is exactly the problem I'm happy to avoid by using excellent bananas.

Now I guess I am going to have to go back and check my spades.

(I am bi-wired, so at the amp end I actually do have a pair of bananas and a pair of spades.)

But I cannot ever recollect any of my spades coming loose.  I tighten them as tight as I can get them by hand and then give them a tiny tweak with a pair of pliers.  I wish they had a hex head, but I guess the reason that they don't is because people would be going ballistic and over-torquing and stripping?