I was just about to start using 2CO for a new site. Didn't hear about the MasterCard issue. Will have to ask on that. They have a 5% reserve for 3 months. Allied Wallet is also very solid but they have a 10% reserve for 6 months. I crossed Payza off the list because they only accept Visa - no MasterCard or Amex and they also have reserves. Neteller is also not a bad option as they are only 3.9% with no reserves or holdback at all, only problem with Neteller is uses have to sign-up for a Neteller eWallet too.
This is all for "high risk" stuff. For normal stuff PayPal or a standard merchant account would probably be the way to go ...