Aside from making the storage larger and slower to perform, I'm not seeing an accuracy change up or down - but I'm also lacking metrics to say definitively, or if there's under-the-hood processes that would take advantage of both sources of data in different ways.
and yeah, my impression is somewhere around the same. it's duplicating text in different ways, but it seems to make it better able to generalize rather than trying to match the exact question/answer format when the user asks it an open ended question