The newer 680 series guns with the Optima barrels are very good compared to what Beretta put out in the past. The ones tested proved to be consistent as far as POI between the O/U barrels.
Some guys like to have different impact points for doubles; a little higher for the first shot, maybe not a bad idea if every club threw the same target presentation - but not likely.
Most shooters grow accustomed to where the "sweet spot" is on a set of barrels, and the newer Beretta 687 SPs have a good reputation for barrel regulation.
The unsingle seems to require a bit more time to dial in, probably due to the weight balance difference from the O/U. Lots of adjustment can make matters worse.
Most folks are recommending aftermarket chokes, as they seemingly give more predictable performance.
Regards, GAP