Spade vs bare wire

Connectors always impart their own sonic signature. Having said that, I've tried bare wire, spade and banana connectors and each sounded good in the context of the system I had then. 

Once I accepted that connectors have their own sound, it's easy to accept the sound of the cable, should they come with connectors. Having said that, I find well made bananas to be a fine choice to go with.

BFA bananas have never loosened on me. What I have now are Furutech FT-212 locking bananas (https://zenwaveaudio.com/product/furutech-gold-plated-locking-banana/ ) and they stay solidly in place.

All the best,
Nonoise

Bananas IMHO are the least likely to loosen.

Spades are good, but only with soft metals. Using very hard terminals, and/or very hard spades leads to easy to loosen connections. WBT makes a type of spring loaded spade I like a great deal.

Otherwise, I like the low mass WBT type of locking banana best. I tried Furutech and they were literally garbage.

I've had the best luck with BFA bananas. They have a very large contact area and if they do loosen from repeated insertions it's easy to adjust the tension with a pair of needle-nosed pliers.