You know guys... there is an awful lot more to shotgunning than the size of the cartridge that slides in the chambers.
There are people who shoot a lightweight, small frame, petite game gun in 28 or 410 very well. They are damn few. Damn few.
At one of my favorite clubs, we have some fine small gauge shooters. They shoot our five stand course in all it's endless configurations VERY well. They also use TARGET shotguns, that you would hardly ever see on a dove or quail shoot.
The average field shooter, meaning probably a small gauge cartridge consumption of less than 5,000 per year, is much better served with a 20 than a 28.
You want to pay your dues and learn to shoot a light 28 well go right ahead. It's a daunting task. I'm not talking skeet targets with a tubed gun or an XS skeet gun. Try a real field 28 on REAL targets like a good SC setup and see how you do.
Experience and knowing ones own abilities helps with gun selection for an expensive hunt.