I have used the Burris FF2 the past two seasons on my Benelli and it is the best turkey sight I have tried. I got two seasons of hunting/killing on the original battery. I am considering a Burris FF3 because you do not have to re-sight your gun when you change batteries in it.
+1. Mine is on a SX3 and I really like it. Probably will get a FF3 for the reason mentioned above plus I think it has click adjustments and it took some time to get my FF2 where I wanted it.