Using a wireless system can allow you to get a microphone close to the sound source you desire and even move with it, without the hassle of cables interfering with your talent or other production elements.  You should know that a brand new, high quality wireless microphone receiver/transmitter kit will set you back a couple thousand dollars but the time you will save in editing and the confidence you will have in the field will be well worth the investment.  I’d rather run audio cables 200 feet than rely on a substandard wireless setup because they never sound good even under the best of circumstances.  I’ve spent hundreds of hours working on tracks (from lower end wireless rigs) that are so full of dropouts and noise that I almost lost my mind trying to make them sound presentable.  Maybe I’m a vain perfectionist but when I got my excellent wireless systems and started using them on all my shoots I finally felt like a real professional.