Whose Medicare plan cuts more?

Mitt Romney and his running mate, Paul Ryan, are accusing President Obama of hurting seniors by slashing $716 billion out of Medicare.
Obama, meanwhile, is attacking Ryan for wanting to "end Medicare as we know it."
These heated exchanges come as both sides look for ways to wring savings out of Medicare before the entitlement program runs out of money. They just differ on who will pick up the tab.
Obama, through his health reform law, cuts the rates of providers, including hospitals and insurers. Ryan, on the other hand, wants to turn Medicare over to the private sector by giving senior citizens vouchers to buy coverage from insurance providers.