I worked there for a year, left in September '76.
The "Old Man," Vince Lazzara had some kind of epiphany and restructured the production to improve the quality at every stage. I believe the primary glasswork was always pretty good, and the joiner work was really good. He had a hissy fit one day when he discovered secondary bonds (bulkhead tabs) poorly done over sawdust and other debris and shook everyone up.
At the same time, he was selling fleets of boats to Stevens Yachts and The Moorings . . . two bareboat companies that were very good at breaking even quite solid boats, so there was a real incentive to toughen them up and improve all the systems.
Vince was already improving the designs to make them more sailboaty (the first Gulfstar hulls were uses as trawlers and motorsailers). He basically educated his clientele . . . moving them up into better and better boats over the years. The upshot was boats of better than average quality.
Unfortunately, many people had already formed their opinions, and Dan y is perhaps suffering a bit from that.