I've used all the sights out there red dot, holo, bead, and fiber optic. This past year I went back to fiber optic sights (truglo magnum sights to be exact), not because I missed shooting at a bird with my red dot, but I did miss some opertunities to kill birds do to the red dot.
The Truglo Magnum sights are good, but so are the williams fire sights and the limbsaver adjustable sights. If price is an issue I would shop around and find which one of the 3 adj. fiber optic sights I could get the cheapest.