In my experience a Tusq nut and saddle can make a big difference in the tone of an acoustic guitar. I have not only gotten much better sustain and cleaner open notes, but also a much more harmonically rich tone on each guitar I have changed out the factory nut and saddles on.
Be prepared to do a little sanding as these are purposely made a little large. But with a little patience, a flat surface, and some sandpaper you can get a perfect fit!