By nature storage will always be a bottleneck. Even if data moves at SSD speeds, that is still time that the OS has to wait for the data to arrive, and nothing can happen until then.
But yes, an SSD would drastically improve general performance.
A spec of your PC will be a better way of asking us if there's bottlenecks, for all we know you have a 3930k and a GTX210. Windows Experience Score isn't even a decent indicator of performance.