I would shoot the one that gives you the best accuracy. I have shot deer with both and have seen very little difference between the two. I am currently shooting 285 gr SSB's because my gun likes them, but when I run out I will switch and shoot up the 50 SST/SW's I have and not see much of a difference in performance.
BTW, I shot a doe with a hastings 547 gr slug this year, broadside took out both lungs. Didn't find a drop of blood for 120 yards till she was laying in a pool of it. BIG holes in and out. I still think they are an excellent slug, and won't base my feelings for them on one kill.