Hyperspace can only go along specified routes, or you have to constantly decelerate and change your course. In addition, with subspace you can pick the point you want to travel to and almost immediately arrive there, which is a tactical boon in a combat engagement. I'd say that over long distances, the two universes' ship speeds balance out.
Oh, and the Shivans would rip the Empire+Rebelllion+Republic+Ewoks a new one. Hell, the GTVA could do it. Their shields aren't as resilient as ours, and we have plasma turrets, repeating lasers, and beam weaponry. However, it seems that all other universes can engage from longer range.