In the scene in the GF3 before the Massacre. Micheal was sayin how joey Zasa is the best dressed gangster and how hes famous. I think he was mocking Zasa, hows he wants to be famous but how the old dons never wanted to be known by everyone as a gangster etc.
I think it also kind of symbolic of how it was in real life. How the new style dons were very different then the old.

Very much so. The older generation never flashed their wealth. They tended to live in smaller homes, dress down, and so on. If I recall, there was a thread here not too long ago about how humble Hyman Roth's Florida house was.

It's interesting how Michael goes from peacemaker between Zasa and Vincent to sarcastic references to Zasa to his face in Atlantic City almost overnight. Why, I wonder? The attempted hit on Vincent?

Speaking of Mafia tradition, etc. You have a rather reserved don in the old tradition like Castellano living in a mansion on Staten Island while the flamboyant Gotti lives in a modest home in Queens.

Zasa was a combinaton of John Gotti (best-dressed, publicity hound) and Joe Columbo (poorly dressed, publicity hound). Zasa's "Meucci Society" = Columbo's "Italian-American Civil Rights League."

Olivant's point about Michael transitioning from peacemaker between Vincent and Zasa to Zasa's antagonist in Atlantic City is well taken. Obviously the AC sarcasm and insults were directorial license, designed to set up Zasa's angry exit and the helicopter attack. But there was a bit more to it:
A subtheme in GFIII is how Michael and Vincent used each other. Vincent maneuvered his way into Michael's party and got an audience with him by sucking up to Connie ("How's my favorite aunt?"). Once he got into Michael's office, he called out Zasa, in effect demanding that Michael take sides with him. Instead, Michael takes sides with Zasa, telling Vincent he was "foolish" to antagonize him and extolling "the goodness of [Zasa's] heart" when Zasa gave Vincent a job. "Make your peace with Mr. Joe Zasa," Michael demands. In effect, Michael gave Zasa a license to kill Vincent. So Vincent, his back to the wall, bites Zasa's ear. Now he's forced Uncle Mike to decide if blood is thicker than water. And Michael chooses Vincent.
Looks like Vincent outmaneuvered Michael, eh? Not so fast! Michael was putting Vincent to the test: how far was he willing to go to show that he really wanted to be a Corleone? IMO, Michael was using Vincent to test Zasa. He hated Zasa, but wanted to see if Zasa would move against him openly. Zasa's attempt to kill Vincent was proof enough: the attack on Vincent was an attack on Michael.
So, by the time of the AC meeting, Michael had nothing to hide--or lose--by openly antagonizing Zasa with his sarcasm. Vincent had served as his cat's paw for making Zasa show his true colors. And Vincent was his man, willing to do any violence to support his uncle. Who used whom?

That, what you call "modest" home where Goti lived is about
$750,000.00 to $850,000.00 dollars in that section. The Howard Beach Section.
Funny thing is that those same home sold for about $37,000.00 when new.

Then watch TV and see what his daughter is living in on Long Island. Now that is some piece of land. Even though it looks run down when you see the show in spots.

Great point TB. Vito used sarcasm, but in a less heavy handed way than Michael. He uses it early on with Johnny Fontaine in the "You can act like a man" scene, where he pretends to be crying. We see it again in the scene right before Tom tells him that Sonny is dead, Vito says : But you needed a drink first....now you've had your drink, so tell your Godfather what everyone else seems to know.

Michael's sarcasm is more direct and it is darker. Snyde comments like "he's been dying of the same heart attack for years," and "you can take your wife and your mistress" show Mike to be a more cynical man than his father.

That's true in the scenes you cited, dt. But in the deleted scene after Connie's wedding, where Vito and Michael are about to drive to visit Genco on his deathbed, Vito's much more sarcastic. "Did your American girlfriend [emphasis in original] get home alright?" Vito asks, rolling his eyes in disapproval. At the hospital, he flicks Michael's medals and asks, "What are these...Christmas ribbons for?" "For bravery," replies Michael. "What miracles you perform for strangers," Vito says. Ouch!!

Ouch is right TB.

One of my favorite snide comments is when Michael is talking to COnnie and Merle -- or I should say avcoiding talking to Merle-- and he says "Why do you come to me? Why don't you go to a travel agent?"