Benelli started a pretty big revolution a few years ago ...with their Inertia guns / vs the more traditional gas operated semi-autos..
Today - Franchi - is owned by Beretta / Benelli ...but I don't know if the Inertia system in the Franchi models is the same as the Benelli models. I've heard it said at gun counters - that the Franchi is just a cheaper version of the Benelli / implying its the same internal components ...but I don't know that its true / or if its guys just selling guns ....
I have a pair of Benelli semi-auto Inertia guns ... both Super Sport models - one in 12ga and one in 20ga. In that model - Benelli put a recoil supression system into their synthetic stock called a "comfort tech system" and I don't know if they offer that in the Franchi line or not. You cannot put it into a wooden stock gun / because the system is inserted into the carbon fibre stocks - and it compresses on recoil / abosorbing some of the energy.
The Inertia Driven system is pretty simple - there is a spring in the bolt assembly - that compresses / the head of the bolt rotates / it moves back and forth based on Inertia ( Benelli says it better on their website ) ...I'm butchering it a little .... but the system cycles quickly, it shoots cleaner than any gas gun because the burnt gas is not operating or cycling the bolt --- it also makes for a light weight gun - low maintenance etc ...
On the recoil side - without the Comfort Tech system / I would say the Inertia guns have about 20% more recoil than a gas gun. With the Comfort Tech system - I think the recoil is about the same as a gas gun. There are some improvements in gas guns - Browning / Winchesters system of Activ Valve ...Beretta's new 391's etc ...so they are faster than they used to be ---but I think the Benelli system is at least as fast as a Remington 1100 as an example / maybe a little faster.
Franchi is less expensive than the Benelli. The problem I have - is I've seen a few of them at my range that have cycling issues. Maybe they were dirty / maybe not lubed ...I don't know. Maybe the system they use isn't as refined as the Benelli system ?? I can tell you my Benelli Super Sports have been extraordinary guns in terms of cycling 100% and no problems even in a 4 day sporting clays tournament ( but that model is selling new today for around $ 1,875 ) ...
http://www.benelliusa.com/shotguns/benelli_supersport_and_sport_2.php
I bought the first Benelli Super Sport in a 12ga, 30" barrel ..and its only 7.2 lbs - because I had fractured a shoulder blade in a cycling accident / and it hurt to shoot my heavy Browning Over Unders ...and to shoot in a 4 day tournament was out of the question...so I bought one several years ago / and shot it all season while my shoulder blade was healing... Now 4 or 5 of my buddies have invested in them as well ...and I've added a 20ga version in 28" barrel ...for some of the younger grandkids to shoot ( and for me to have another gun truthfully ) ... Today I use the Benelli as my travel gun -- easy to ship on airlines / does everything pretty well - skeet, sporting, bird hunting, etc ...and I can get by with one gun traveling. I also use it as a "foul weather gun" when I don't want to take a nice Over Under, wood stock gun, out in the rain and sleet ...and it does great there too...