It depends.

If you have a strong product with a lot of interest surrounding it, possibly even some pre-sales.. you will not benefit much from being in a "premium location".

If you have a startup in "Silicon Valley", and you have enough funding to be there. Then you could use your "premium location" to attract investors to prop up what would otherwise be a failed idea.

I would say that being in the US does help a lot simply because you get access to a lot of infrastructure and supply chain benefits that are not as developed in other countries.

 Also placing your self in a "College Town", can really boost your chance of success. The US "college culture" lets you hire premium talent at a very cut rate ( if not free ).

Well that depends. I am planning to have the same  for my start-up.It depends on different factors like the market, demand, competition etc. Different factors come  gradually once you plan to start.There are many countries you  can have for the start up but you will also have to look for the factors so that you can start your company for your benefit.