Kind of late to the game, but I went through this EXACT deliberation a year ago. It eventually came down to a handful:
Beretta A300 & A400
Benelli SBE III, and Super Vinci.
Win SX4.
Rem V3.
Fabarm L4S
Retay Masai Mara.
>>> All in 12ga<<<
I shot all except the Masai Mara, and the A400.
The SBE is a nice gun, but not as nice shooting (for me) as some of the others. It's inertia, not gas, and a difference is noticeable, but not a deal breaker. If you have a long dove day with many rds, I suspect you will feel the difference more.
The Beretta is nice, but again, did not shoot as well as others (for me) and did not feel as natural when pulling up.
The Fabarm shot the best/softest (for me) and fit well, but was just barely better than the Remington, although it had superior build quality.
It then came down to either the Fabarm or the Remington.
I got the V3, and have since put about 700 rds through it. It shoots extremely well, is softer shooting than most of the others, and had the best price point. BUT, Remington was just broken up in bankruptcy court and, although their firearm business will continue (possibly/probably under a new name) it may be difficult to find one in the near future.
I WAS going to get the L4S, but could not justify the extra $$$. In retrospect, the L4S, IMHO, is the best of the group, and worth the money. I may pick one up, as I like the way it shot, it has a very good build quality.