Student loan guru Mark Kantrowitz says he got a sneak preview of Sallie Mae’s new private student loan that will become available next week.

Kantrowitz says in an he likes some of the features of the “Smart Option Student Loan” and encourages other lenders to adopt them:

For one, the Sallie Mae loan requires borrowers to pay at least the interest while they are in school, so that interest doesn’t snowball while students are in school. If you can’t pay the interest while attending classes, you don’t get the loan unless you have a co-signer.

Secondly, the loan term is 5 to 15 years, not the usually 20 to 25 years of other private loans.

This new loan will replace Sallie Mae’s Signature Student Loan, says Kantrowitz, who publishes FinAid, an online provide of financial aid information.

Requiring interest payments while in school will keep the loan costs down for students, but it also helps Sallie Mae’s cash flow and will keep the borrower in touch with the lender through monthly statements, Katrowitz says.

Katrowitz crunched some numbers and found that the new loan could cut the interest paid over the life of the loan by about two-thirds compared the standard private loan.

 The major drawback, he says, is that borrowers usually want to defer interest payments while in school, even if it costs them more over time.