The standard saddle does clash a bit with the gel passenger seat, since they are not covered with the same textured material.
I have the gel low seat and the gel passenger seat, and my family (kids or wife) are fine with the gel passenger seat on rides around town, but I haven't had them on any long trips on it. ANYTHING is better than the stock RIII Standard passenger seat, but if you intend to have a passenger for long distance, or most of the time.. you might be better off with the one piece seat.