Some of the changes were cutting the priest and incorporating characteristics into the Jackie White role; eliminating Arthur and by extension, the love triangle; and changing Gideon's child to a daughter, Ellen.
The shipyard's plight led by Jackie (who now is the one hiding his illness while trying to keep the yard going) now is the main story, with Gideon occasionally popping into focus but no longer being the driving force at the center against a backdrop involving the yard. It's a bit of an anvil, but they're trying to shut down the yard as the Utopia is being constructed and there's more debate with a new character, the Baroness, about the politics of closing the yard and selling the ship for scrap.
Gideon is softer than depicted on Broadway and blends into the background for a bit. I missed following his character's angst-filled arc as the means to hook me into the story. "All This Time" is now the rock song Ellen, an aspiring musician who wants to run off to London, plays as she envisions making a go of it as a musician. "And Yet" now serves as Gideon's reentry to Wallsend but doesn't have the same pop to me. With the rewrite to Ellen, the story also loses some parallels I loved partly because of the double casting of Young Gideon/Tom and "Ghost Story" was also cut.
The female characters are stronger in the revision - although Meg reflects on Gideon, she's not as wistful, and with the increased prominence of Jackie, Peggy also gets more time front and center. I know the context isn't really different, but one thing I hated about the new version was how sudden "Show Some Respect" seemed to come about. The raucous transition felt so abrupt in Toronto, and I don't remember it being so unsettling in NY. (I think the context may be the issue, IIRC it's at the bar wake originally but now feels like it's happening graveside.)