Benefits: As long as there's no pentalty, you pay less interest over the life of the loan (If you're paying it off that early, you sound like you're going for a 10 or 15 year possibly?) You feel better when it's paid and have the freedom of no monthly mortgage payment.
Score impacts: If you pay it off early, it will end up spending less time on your credit report, since it will fall off 10 years after being closed/paid-in-full. I actually have some loans that are set to fall off in two years, they are perfectly good, clean, old accounts and will remove their good history from my file, it's just how it is. (I'm fine though, I have 47 accounts reporting anyways! - No worries, most are closed, old accounts, gotta love student loans.)
Also, with mortgage accounts, consider the interest rate vs some of the other accounts you have to pay, I would pay down higher rate loans faster compared to the mortgage. For me, sticking to minimum on student loans is my best option if I still had my mortgage payment due to the very low interest rate on SL. It's lower than most mortgages people are getting. If you don't have other accounts you have to pay could you instead invest the money and get a higher return on your investment compared to how much you pay in interest.
If you just want the freedom of not having that payment sticking around, then by all means, pay it off. I would recommend you have savings, first and foremost, before dumping all your earnings into the mortgage, however.
