If its really easy for you to switch, I think 15 is great during slower (non-score release) periods. During heavy traffic times, 30 is a lot better because of the amount and frequency of posts. This may become less of an issue if the AICPA gets its act together and releases scores on a more consistent basis.
I was scrolling down the threads and then all of a sudden the threads stopped and I was thinking “Hey! where did all the threads go?!” But then I realized you probably switched it to 15…
I think what Minimorty said makes sense…During busy times when threads keep popping up, more on a page would probably be better. But when posting is less frequent, it is not necessarily necessary to have so many on one page, and it would also benefit those looking at this site from a mobile…(If it's easy for you to switch from 15 to 30…)