I've had better mileage with single rolls over x11 rolls lately (~6 golds from single rolls vs. 3 golds from x11), but really, with these rates, it depends on if you want to spread out your disappointment or you want to be disappointed all at once. You shouldn't expect much else.

Single rolls (are supposed to) have the benefit of stopping when you pull something good. Then again, I went a full 25 rolls before I got Lilac (a silver) during her spotlight.

Bottom line, plan out how much you want to roll, because the 11th roll generally doesn't make a huge difference in the end.