I bought a Suport Sport a little while ago and just recently added a Franchi I-12. I have mostly owned O/U's but recently have been getting into the Semi's and I am finding that a lighter and longer semi real handles quite beautifully in comparison to the O/U's.
So, here are my observations between the Farnchi and the Benelli.
The Benelli appears to be a little better over all quality as you would expect since it costs twice as much. The Franchi fit, finish and overall quality seems real good though and I am pleased with this. The Benelli crio treated barrel and chokes do seem to stay cleaner than any other gun I have owned.
There are numerous discussions on the forum about the I-12 action and its similarity to the Benelli. This should clear it up. The Benelli has a small arm attached at the rear of the bolt that pushes against a cup at the rear of the receiver. Behind the cup is the recoil spring that is located in the butt stock. Because of this, there is very little added weight or drag to the bolt. The Benelli is FAST! REAL FAST!
The Franchi bolt looks almost identical however instead of the arm, cup and buttstock located recoil spring it has the following; the bolt sits inside of a long and somewhat large set of steel arms. the steel arms go forward all the way up to the front of the foregrip. The recoil spring is located inside the foregrip where the steel arms pull against the recoil spring instead of pushing against it. Because of the steel arm bolt carrier design the Franchi is slower than the Benelli. I would rate the Franchi speed as Medium. (Remington 1100 would be slow for comparison sake).
Both guns are very easy to disassemble. The benelli is easier to clean the receiver since it has a 2 piece receiver and essentially the top of the receiver comes right off. The Franchi receiver is still easy to clean though and in fact it is easier to clean the Franchi recoil assembly than the Benelli. If comparing the Franchi against a Benelli one piece receiver then it is roughly the same ease of cleaning.
The Benelli handles extremely well. I have the 30" barrel and it is excellent for sporting clays. It is good for skeet except on a few of the shots the longer barrel is a little slower to get on the bird... and with skeet barrel speed can really help. Now for the real surprise. The Franchi in my opinion handles EXTREMELY WELL. It is a meduim weight gun and swings perfectly smooth with a great balance. I have only had it a few days and I am very glad I bought it. Quite frankly I can not believe a gun in this price range handles this well.
The Benelli has been super reliable feeding anything I put in it including 1oz & 1 1/8 OZ #8 and #9 from Remington, Federal and RIO. The Franchi has had about 15% failuire to feed the second round using Federal Top Gun #8 1oz loads. It appears that some of the rounds just do not have the snot to cycle the load. Using Remington Gun Club #9 1 1/8 oz loads and using Rio #9 1oz loads the Franchi was 100% reliable. I tried two 7/8oz loads and Mr. Franchi told me to forget about it. The Gun is brand new with only 200 rounds through her so maybe it will loosen up and handle the Federals. It does appear that the gun will be ultra reliable if making sure to buy loads it likes. I will experiment more and report back if I find out more.
I really like the I-12 and am very glad I picked it up. I would definately recommend it for a skeet, sporting clays or hunting gun as long as it fits you and you like the looks, which I do. For what it is worth, the Benelli Super Sport is an incredible gun, many people ask me about it at the range and want to try shooting it and everyone of them say the same thing, "it shoulders and points better than any other gun they have picked up". The cordoba is the exact same gun with different finish and wood and I found it to feel this way when shouldering them in shops too. Highly reccomend the Super Sport and Cordoba too. But if you want a shot gun under $1000 you will be happy with the Franchi.
I hope this helps anyone who is considering either of these guns. let me know if you have any questions.