just to keep this updated.
we switched today. we have quite a high volume and so far we haven't had any customer queries regarding this change or noticed any drop in orders. obviously one day is a very small sample, but still the start has been encouraging.
we have noticed a higher % of people choosing to pay with paypal though. we don't get many chargebacks through paypal, but really we are in the same boat as visa, pre-vbv), as paypal will also refund the customer first and ask questions later.
hmmm. i'll update in a while.