Absolutely do not get caught up in the scenario of using different cables for the highs and lows as this causes problems at the crossover point. See this article from Vandersteen,This is not a problem especially if you have a pre-amp or receiver that incorporates Audyssey or something similar as it accounts for Phase and timing problems. I have found that Bi- amping ( using two sets of speaker cables and two amp channels ) using provides a more robust and open sound . Better separation of instruments or sounds .
All i can say , is to try it for yourself . Some people will swear that there is no difference, but i disagree.
Depending on the power of your amp, the difference may be small.
If your amp is say 100-150 watts per channel, you would be more apt to hear a difference, versus a larger or more powerful amp.