I am not an Ithaca lover, but the current ones are no heavier than the old ones with the steel receiver from what I have seen. I doubt anyone has a scale accurate enough to measure the difference between steel alloys.
but they are heavier (a couple lbs heavier)
I can see that I had 8.4 instead of 7.4 in mind, which is erroneous
HOWEVER the actual numbers are:
For a 16ga. 6.2 lbs -vs- 7.4 lbs , actual weights and weights published on their site. the barrels are thicker, yes I have micrometers, yes I have mic'ed the barrels. yes I have Ithacas to compare the new to the old.
the barrels are substantially thicker. a 1956 16ga measures .760 in dia at the muzzle, a King Ferry (Ithaca moved to King Ferry after one of their sales) measures .792 at the muzzle (moving into the steel shot realm) and the new Upper Sandusky barrels use a heavier alloy than the King Ferry barrels.
That extra wall thickness to accomodate steel shot adds weight.
the same holds true in the 20's and 12's. as stated, the current ones use a heavier alloy and are rated for steel shot. while you can get away for a bit with steel in the older ones, an older full choked barrel would eventually have the choke removed
the downside to the new Ithacas are that they are a bit pricey. a Browning BPS costs substantially less than a new Ithaca.
for example at Cabelas, on a side by side comparison you can buy a BPS for $599.99 the comparable Ithaca is $849.99.
Ithacas are a niche gun, you either like them or you don't. You either like the new ones or you don't. They handle and carry superb, especially an older one. But you have to be careful about what you are buying in an older one, as they have one real bad fault, when you store them standing up, oil from the receiver runs down into the stock and eventually softens it up enough to rot the wood and cause it to split.
But are they worth the price differential ? To me, yes, to another person, probably not.
They are go bang and the rabbit, duck, pheasant, goose, turkey, clay target etc receives a dose of lead shot, just the same as with any other shotgun.