At some level there has to be something to them besides mere weight.
I have had one in a M12 trap gun for probably 40 years. I would have a hard time slamming my fist on the table and saying it makes a noticeable difference, but on two occasions I have come off the line and people who were watching approached me and asked if the gun had a reducer. You have to wonder what it is about that gun that caught their attention and lead them directly to the reducer.
Years ago an acquaintance had a Remington 3200 with twin reducers - talk about going for broke. I shot doubles with it once and it was the most amazing thing. The gun vibrated a little bit, but it sure as heck didn't move that I could tell!
I think reducers are like porting. If you shoot two guns, identical except for the reducer/porting, side by side, there will be little doubt in your mind which is which. If you just pick a gun off the rack, you'll never guess if it has been modified or not.
