That's not true. The fees card issuers disclose are inclusive of the network exchange fees (i.e., the 1% charged by Visa/MC). So if Citi/Chase/BoA/etc. disclose 3%, Amex discloses 2.7% and Schwab discloses 0%, that's what you pay. They can't charge you more without disclosing it.

I've personally pored over a lot of data comparing transactions between different credit and ATM cards (I have a friend who splits his hotel bills between two or three cards at checkout whenever he travels overseas just to see how the exchange rates compare), and all signs point to the fact that Schwab and CapOne "eat" the 1% Visa/MC fees and do NOT pass them through to customers. Purchases on those cards almost always fall within the interbank trading range on Bloomberg for the day (or day before) the purchase "posts" to the card. Sometimes they are slightly off, but never consistently so.

The only hidden fees you can end up paying with Schwab, CapOne and similar cards are if you make an overseas purchase and have the merchant convert the price from local currency to USD before running the transaction (a practice known as Dynamic Currency Conversion). In that case the merchant (or his bank) can use whatever exchange rate he wants (often 5-10% worse than the interbank rate). But that's the merchant ripping you off--not your credit card company or Visa/MC, and it can be avoided by insisting that merchants always run transactions in local currency.