There is a cut of the sail thas has panels utilizing radial cuts and stitching; and, then there is sailcloth that is woven utilizing (for example, Dimesnion as a manufacturer) weaves of various fabrics and their placement in the more horizontal panels in order to distribute the load.

For your size boat and use, I think a quality Dactron (Polyester) sail would the best value, mildew less, allow for ease of cleaning and general handling. In addition, it will cost a lot less than a laminated sail from more exotic fabrics (Spectra, Kevlar, etc.).

What sailmaker(s) are you looking at? Some have proprietary materials (like North); others use generally available, 3rd party providers. I think a durable sail is a function of design, material, and quality of construction/detailing. If you're buying a sail in the mail...then you are going to have to deal with those issues "long-distance".