No more “guarantees”, the loans are direct and the government is making tons of money on them with the Grad Plus loans being the most profitable. The government’s cost on those is a spectacular -40.62%! The cost difference between that and the private market is enough to merit some serious number crunching before you decide the best choice.
http://www.cbo.gov/sites/default/files/cbofiles/attachments/44198-2014-04-StudentLoan.pdf