The main benefit of bananas or spades are the easy connection and to stop the cable oxidizing (when the copper goes brown from exposure to the air).
arguably stripped copper may be slightly better because of fewer connections (the bananas) but you have to keep stripping it off to reveal fresh copper thus shortening your cables each time!
I have always used the banana plugs as I find them neater overall, I have tried connected cable to binding post without plugs and to be honest I my opinion I couldn't hear any difference.
If you don't usually disconnect your loudspeakers cables, there's no reason to use bananas or spades. Just connect them directly on the binding posts. Bananas and spades won't improve the audio quality of your system, they'll just make your life easier.