Vandersteen used to provide only for bananas. Now, some of them at least, only allow for spades of a certain size. The only thing you don’t get is a choice.
While theoretically there may be a difference, and logically spades appear to be a tighter connection, it’s actually about surface area, not pressure. I use bananas because they are more convenient and I hear no sonic benefit from going to spades (my mit cables allow me to use either). Imho, there are just too many variables for there to be one correct answer in any event.
edit: lol - just realized I’m posting to a 10 year old thread. Oh well...