I ended up with an extrema and my buddy had an M2 last year and switching to the Vinci this year.
Several reason I ended up with mine instead of the SBE.
1) LOP and drop in stock are both adjustable. With the benelli, if the lop isn't right, you'll have to buy another pad. With the beretta, I can try out 4 lop adjustment out of the box and I ended up finding a stock dimension that fits me great.
2) No recoil spring in stock. After a long day out in the rain, I always make sure I dry and clean the recoil spring. With the beretta, there is nothing in the stock, just one less step to do after a long day on the field.
3) Rust resistance is one of the best I've seen short of a full stainless rifle. The outside of the barrel is some sort of anodized finish. Instead of watching the bluing rust away in the rain, I am now confident that the gun will not rust until I get home and take it down. No more hosing down a wet gun with G96 and shoving it in a gun case and drive an hour home and worry about rusting.
4) I know you said recoil isn't an issue, but pumping out 20 rds or so of turkey loads including some 2oz 3.5er, it nice to wake up and not see a nice purple bump on your shoulder.
Its a bit more bulky in built, but not too much more in weight comparing to SBE.
For 400 bucks less, I think they beretta is a better deal as well.