What Matt wrote about the" Benelli Click" is spot on, especially with the older guns. I've read that it is not a problem with the brand new guns. I like my old M1 just fine. I know it's quirks and it knows mine.
As for the 1100 versus the 11-87. I have owned both and the 1100 is far superior in every way in my experience. When the 1100's were the must have guns for skeet. The saying was "They're made from Prince Albert cans but they sure do work", and they still do. Not many sit on used gun racks for very long, and the new ones have a hefty price indeed.