When I started clay shooting, my father, who had been into regional and national trap shooting competition with very positive results for long time, told me to buy as my starter weapon either a Beretta 680 series or a Perazzi. Anything else wasn't worth to be considered in his opinion.
At that time I was unsure if I would have enjoyed or not clay shooting, so I chose to stay low on budget and away from Perazzi, and got myself into a 2004 Beretta 682 Gold E Sporting. I did my research and any reviewer was positively talking about this over under shotgun.
The gun came with a selective trigger commanded by inertial block, but I soon found there was no way to make that trigger reset on upper barrel after first shot on lower barrel. Otherwise choosing to shoot first upper barrel, the trigger would correctly reset on lower barrel with absolute reliability. The worse thing was that more I digged into the problem, further I found forum threads, discussions and other topics talking about that same issue experienced by shooters all around the globe. It was pointless to have it tried by other shooters, it wasn't an issue due to shotshells or my shooting stance.
I guess the reason is one of those mysteries yet to be solved, but if I knew this before I wouldn't have chose this gun in the first place. It seems that people having this issue only solution is to convert the inertial to mechanical trigger. That's exactly what I had to do in order to solve my problem with the gun, and have it consistent.