I think perhaps the question is not the Moda fabric, but what fabric is she comparing it to? If her other quilts were made with fabrics from "big box" or chain stores, the chances are good they had a lot of sizing and other finishes on the fabric that made it seem stiff, or thicker. Is it possible even that a fabric blend was used? Or, perhaps the fabrics were all solids from Robert Kaufman's Kona Cotton, which we all know has a higher, denser thread count -- the very reason why many quilters really love it.
Moda has such a marvelous reputation among quilters that it's hard to believe she has a questionable pack of their fabrics. She can use virtually any well-established manufacturers quilting cottons with no problem.
Jan in VA,