These are literally the best sounding strings I have had the pleasure of playing on my Santa Cruz OM guitar. I tried Elixir, D'addario, Martin and DR strings. These Optima Strings suit my particular guitar best. The midrange is particularly bell like with sustain, clarity and punch. Slightly higher tension for the same guage than all the other brands which can be a plus or minus depending on the guitar you have. I will not be going back now.