I have had both. My first 1100 was over 25 years ago, my last 11-87 was an SP model. If the ammunition that is available today, was available then, I would have never owned the 11-87. I spend more time with clays than anything. Plenty of 2 3/4" "magnum" loads available to cover any need for a hotter poke. I've given up 3" magnum shells, no real need except high ducks. Kent took care of that with Fasteel. Now with the newer heavy metal shells, I don't see a need at all.
IMHO
Ris