So is there a good explanation of why banks would use Ripple and why it's better than their existing options?
They use XRP, the ripple crypto currency to hold the sender and receivers funds during the transaction.
See also this video that explains it really well => https://www.youtube.com/watch?v=Q2YHhLkOO9g
and this one, which is more technical and explains their blockchain technology / xCurrent software. https://www.youtube.com/watch?v=bU79HunxJp8
Source: https://www.reddit.com/r/Ripple/comments/6jd9w6/this_is_the_...