I've done both, fiber optic sights installed to the vent rib and just a single bead...I think it's just personal preference...I have 2 shotguns set and go back and forth between the two...One is actually a 2 3/4 1100 and it patterns very well, I also use this gun for deer, pheasants, squirrel, rabbits, quail, etc...

It really depends upon the hunter and how well he can shoot as well as how tight that pattern is at say, 15-20 yards, that's when a sight helps...

My turkey gun came with a set of TruGlo sights. The rear set (green) got loose and in a flash of brilliance I put it somewhere in the house so I wouldn't lose it. It still hasn't shown up.

Anyways, I'm left with a red fiber optic bead near the muzzle. So far, everytime I've put that red dot on a turkey's neck it worked. I called TruGlo 2 weeks ago and they're making a replacement for my gun. They've changed their sights some since 2005.

BUT...I am thinking of putting a scope on my bird buster.

I've got a small bead halfway down barrel and a fiber optic front bead. I like this set up and it shoots well to 35 yards. I've had a red dot on it before, but went back to the bead... Works wells for me, so I keep it simple.
-Jake