20 gauge for ducks?

Thanks for all the feedback guys. You have helped me make up my mind ;-) ..... I just posted my 12 gauge in the For Sale section.

A 12 is for one box a year shooters.
A 20 in the hands of a "hunter" is still too much gun due mostly to the dynamics and technological advancements in ammo.Thier in lies the key. Use good ammo for ducks.Use the best ammo for geese and use anything else for everything else.
It has been said by many writers that two people walking together with the same skill and a bird gets up.The one with the lighter firearm will be on that bird 8 to 20 yards sooner.
Enjoy your 20. One thing you didn't say is what kind you were looking at.
In order for you to take advantage of the 20's virtues don't get one that weighs like a 12, or even a 16
My .02

My duck hunting consists of opening weekend for 90% Teal and the odd mallard over decoys. I was actually considering switching to a 20ga. Teal are tiny, just hard to hit. Not sure a 12ga makes it easier to hit them, just more payload which on a small bird may not be needed? I'm not anywhere near a serious duck hunter though so I'll sit back and listen to those who are.