I'll add to the chorus of people telling you to move over to Vanguard.
I did the same thing a few years back (not from Scottrade, but a similar situation) and it's been great.
It was a bit of a hassle one time to make the move, but ever since it's been so much easier since the majority of my investments are in Vanguard accounts.
If you have any questions or issues with moving I would highly recommend you call Vanguard. For obvious reasons, they were much more willing to help me move my money to them than the previous company was in helping me move my money out. The Vanguard reps walked me through the paperwork, etc to move my accounts over and made it very easy to make the switch.
And, once at Vanguard I was able to go from VTSMX to VTSAX seamlessly.