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