Actually, I believe you are giving up wear factors. Most people are choosing Sunbrella upholstery fabric, not outdoor or awning fabrics. While you have many colors and patterns to choose from and Sunbrella has moisture and uv resistance, its "double rub" characteristics, I believe are around 50,000+ which is good for an upholstery fabric. However, I remember Tammy telling me that their commercial grade, standard fabric is 200,000+ double rubs. You can check with Tammy on that. There is no doubt, that the standard fabric will outperform the standard Sunbrella over time. You have to decide just how much wear the cushions are going to get and if you like the standard color/pattern.
Based on over 4 years of use now, I CAN recommend, as I have in previous posts, that, regardless of fabric that you have the cushions done in ALL fabric. I would never again have the vinyl on the bottom as it is less than $4 / yard fabric and the sewing causes actual punctures in the material (unlike fabric where the needle goes between the weave) and sets them up for failure. So, don't pay for a $30/yard cover fabric that has a $4/yard vinyl backing. Just saying...