RE: Which gun do you prefer?
Most won't bring an O/U waterfowling because they think it's a price thing. They'll spend 1000 on an autoloader but a shotgun that cost 2-400 more they get qeasy.
They real reason IMHO is an overall lack of waterfowling skills. Most today think they need 3 or 3 1/2" loads. There is nothing that feels and handles as good as a O/U that fits. With 2 3/4 " loads that pattern properly and the knowledge and skill to bring birds in over the decoys there's no reason not to use an O/U