Maybe Beretta changed the chokes for 2006, if they did, they need to update their website.
My field gun has flush fit tubes, while the Gold Sporting comes with extended sporting clay tubes. Perhaps they changed this for this year, but most hunters dont want a stainless tube sticking out of their barrel shinning in the sun light.
Another difference between the gold and gold sporting is the rib width. 1/4" compared to 10mm.