Hi,
I have the captain's chairs also, as I did not want to pay $500 for the bench seat. Aside from the additional (all beat small) seat, having the bench in the second row would better confine loose items that you place in the back of the ST. The captain's chairs leave about an eight inch space for items to roll/slide through to the second row area when you fold down the third row seats for more cargo space. I imagine it to be a little harder to get into the third row to sit with the bench seat too.
Cheers,
Ron