Bare wire is better. The transition from one material to another is always a problem because the music signal can become degraded. Spade and banana plugs are convenience items.
Modification of speaker cables
I have a set of MIT's 750 biwire speaker cables. They are terminated with spades. I have just purchased a new amp that has binding posts that are larger than the spades will fit. Will there be any negatives to removing the spades and going with the bare wire? (other than resale value)