Like Irv said, security and safety are big. If you're not experienced handling the bare wire, then theres always the odd change a random strand could escape you and touch something metal and you'd be in some trouble. If the speakers are ever knocked over, or if there are kids who could catch a foot on the wire, banana plugs are a must.
Just stuff like that, or if you'll be plugging and unplugging often. Otherwise, like Irv said no audible difference.