I have never owned a SBE-2 or a Beretta X-trema. But I have owned a Browning Gold 3.5" and that being said I may have a bit of a say in this topic. I dont argue that the SBE-2 and the Beretta are great guns, heck there at the top of the waterfowling shotguns class. But here in Canada either one costs upwards of $2000 by the time your done.
I can say owning a Browning gold and buying a SX-3 next week this design costs $1200 when your done, and its as reliable as they come.
Someone said the SX-3 isnt proven yet, its exactly the same design and system as the Browning Gold and Silver models. These guns should be held in high regard in the Waterfowling crowd. I like the SX-3 potential, light enough for walking corn fields for pheasent. Shoots light loads for clays very well!! And the ability to shoot 3.5" shells for geese and turkeys.
The SX-3 is a great idea for a do it all shotgun. You can save almost $800 and get a gun that is just as reliable as a SBE-2 or any Beretta. Save the money for decoys and other expences of the sport. Your mistaken if you pass off the Browning/Winchester "Active Valve System" as an unsuperior system. It's by far the best i've shot with, and there are a tonne of people who sware by it!!! They are great guns that I would be happy with at twice the price!!! Sorry for the rant and if you can afford the SBE-2, congrats!!! The Sx-3 will be getting some respect very soon!!! Happy shooting!!! Cheers