I've found that string material and construction, is much more important than brand name. Brass and Bronze give a brighter tone but dull or corrode faster. Phosphor Bronze tend to last somewhat longer. If you want a richer but somewhat softer sound Monel is available. "Silk and Steel" are somewhat muted but easy to play and are great to mellow out a rough sounding instrument. I like D'Addario Flat Tops (which are a semi flat wound Phosphor Bronze)on my Martin.

Mike