FINALLY someone with the Browning!!

Andre: comments, experiences, please!!
I have been considering the Antonio Zoli Focus, the Browning or the Beretta.
A friend of mine has the Beretta but it suffer from some (unspecified, I'm afraid!) problems that he tells me are typical of the model, and consequently he's been dissatisfied.
The Zoli I know through their shotgun lineage - and this forum has provided me with a load of other useful info; but the Great Unknown to me is the Browning!

I tried it out at an outdoors fair, and it certainly fits me like a glove; even better than the Zoli.
Also the sights are good, the woodwork and finish very nice plus the barrels are adjustable via some sleeve arrangement.
But otherwise: how is it to shoot, reliability, any issues? There are two models: either to be recommended over the other? Is is cock-on-opening, or does it have a cocking lever as per some German guns? Accuracy OK?
Can switch barrels be obtained? It's based on the 20 gauge shotgun frame, so one would assume that combo and/or shotgun and/or other rifle caliber barrels could be obtained. Do you know if this is so?
Is the 9,3mm the largest? Zoli not long ago came out with a .450/400 which is interesting, indeed.