Should I pay a larger % of my undergrad student loans back or enroll in my work's 401(k) profit sharing plan?

If I put 3% of my salary towards a 401(k) my employer will match it 100%. My goal is to pay back my student loans as quickly as possible, and if I decided to fund said 401(k) it would slow my loan repayment schedule down by 3 - 6 months. Yet, the interest rates on my student loans only average 6.25% (which is also the national average) and I appreciate the time value of money. Any advice you could offer would be appreciated very much.