Silverlake: glad you like your boat. As mentioned, YMMV: it's possible TMI was building some boats better than others. But on the whole, their reputation is terrible. Especially among Bucc18 sailors, who are content with mediocre quality. (The Chryslers and Starwinds weren't exactly well made; my '78 Chrysler has all kinds of issues, most of them from the TMI factory while under Chrysler Marine oversight.) But the TMI boat are shunned.
I got the information about TMI's corner-cutting direct from Gibbs and McAlpine-Downey, explaining why they pulled the molds from TMI. They didn't want their name on the boats coming out of that factory. They demanded quality improvement & that TMI build the hulls to specification; TMI ceased royalty payments; it got ugly. TMI went bust, mooting the dispute; and Wellcraft/Starwind/Gloucester began producing Bucc18s.
It was a tough time to make plastic boats. Lots of US boat companies felt pressured to economize on materials and methods, and anyone buying a craft of that vintage should look hard at the layups. TMI began as a troubled, undercapitalized business and sold off its sailboat assets within months; your 1981 TMI-30 might even have been made by Ticon Yachts
, which bought the rights in that year. Do you know where it was made?
ETA: I've altered my first boat to be less categorical; I'm only personally familiar with the smaller boats of the Chrysler/TMI legacy & am not qualified to disparage the larger models.