2Checkout does a solid job on fruad screening. Fraud screening isn't perfect though. We had purchase a company who was using 2 Checkout and instead of cancelling all the subscriptions and moving them over to our merchant account we decide to allow 2Checkout to handle the subscriptions.
A new order was placed prior to us switching new orders over and our manager was reviewing the order. It was quickly tagged as fraud. 2Checkout took 48 hours to tag it.
We save ourselves money. Then we switch over to our merchant account and started using MaxMind + phone verification. It is easier then losing the $29.00 per chargeback.
If you have not found a new processor yet and you meet the requirements I would recommend CDG Commerce. They do a solid job for us and give you a lot of fraud defense systems for free.