This is what my inner instinct says - that SIP will be better capitol in the long term. SOB can have slight edge in food and commerce, but it relies on presumption we will want to put our city2 and city3 in such a manner to help the capitol, where the real game may require us to take advantage of other city locations and opportunities which arise.
With such close vote I am sure we cant go wrong with either capitol. If there is time and will from people making the "real world" test up to turn 100 and give results, we would be able to make much more informed choice.
Otherways I would go with SIP based on my instincts to bet on something sure.