I've played the new italian heavies on the common test server. Here is my quick run-down:
Carro P.88: Mobile heavium with no real armor to rely on. Play it like a French or German tier VII heavy. (Tiger I, AMX M4 45, stuff like that) Take advantage of flanking if possible and don't expect to be on the frontline unless you're matched against tier V.
Progetto 54: The mobility on this tank is medium-like, except the traverse speed is bad. Recommended rotation device. The armor is just alright, but you will get buttered by gold, especially your turret. You can't really play hull down. All-around worse than the Bisonte in my opinion. One funny thing is that the lower plate is auto-ricochet from many angles on level ground, so try that out.
Progetto 66: The real gem of the branch. The turret armor is reliable against tier VIII-X, especially when hull down. The hull armor is okay, and becomes good when hull down. Gun has great reload times for the good alpha, and the mobility is really smooth for a tank of this size and punching power. Gun handling is pretty good too.
Rinoceronte: If you are a competitive player, the branch ends at tier IX; Rinoceronte is a fun joke, basically. The turret is just okay (but useless against gold) when on level ground, very solid when hull-down, and absolute poop when below the enemy. The hull armor is unreliable from almost any angle, so try not to ever expose your hull. The reload times are excruciating, especially with an empty magazine; so while it is fun to dump 3x 490 on an enemy, you'll be left feeling rather useless for a minute or more while you rebuild your magazine. It's a fun tank to play, but it is not competitive, and it is frustrating at times. The only place this tank is a serious contender is on a ridge line.