Spades are usually preferred. When I got my stealth audio cables terminated in banana however, they felt very confident about their specific banana process
In the past they recommended spades but their new process bananas perform 100% as good as the spades, both tested sonically and in measurements. They also bi-wired the ends for me and apparently the bass section is doubled up
I much prefer banana they come out cleanly from the speakers and its easy to make the quick turn
If I was buying a random brand though I would probably look at spades unless I was guaranteed on performance