Are you eligible for student loan interest tax deductions? If yes, don't forget to add that into the equation.
The rule of thumb of maxing the tax-advantaged accounts and then paying off the loans sounds like good advice to me. My SLs are under 2% @ $189/month though, and I have no intention of paying them off substantially early. OTOH, my car note is at 2.79%, and that payment annoys me to no end, so I'm killing it pretty quickly even if the math says it might be better to invest.