Taiwan boats, any good?
My mother and stepfather were in the boatbuilding and importing business during the period that the boats were built that you are considering. They had their boats built in Taiwan. The boat building community in Taiwan was quite close knit. Mom used three different yards during the time that she was in business and so spent quite a bit of time investigating the various yards over there in order to pick one that made sense for which ever model boat she intended to have constructed and so knew the yards quite well.
Just like the U.S. there were huge differences in quality between the best quality yards and the worst. Boats like the Formosas were generally considered extremely poor quality relative to boats built at the better yards.
In a general sense, some very well built boats came out of some of the yards, but for the most part they still had some big design and quality control issues. Taiwanese boats from the early 1980''s tend to have very bad blister problems (far worse than found on most other areas of the world) due to the poor climate control in which these boats were built, the wholesale use of accelerators, careless batching of the resins, and resin rich laminates. There was a tendancy to layup thick hulls with a lot of non-directional material (mat), improperly handled poor grade fiberglass fabrics and resin rich laminates, which tends to produce poor impact resistance and an increased tendancy towards fatigue. Structually many of the Taiwanese boats tended to be crudely done lacking the kind of internal structure systems that were becoming the norm world wide during this period.
Depending on the yard, many, if not most, of the yards tended to use a lot of non-marine plywood even in such vulnerable locations as deck coring and structural bulkheads. Many, if not most, of the yards tended to use knock off fittings so that replacement parts are imposible to find and the useful lifespand is comparatively short. Poor grades of stainless steel fastenings (or even steel fastenings within the interiors and concealed locations on the boats)were typically employed. Many of the better yards were still using black iron fuel and water tanks. Tinned wire was virtually unheard of. Electrical panels and fixtures were generally knock offs of better quality equipment and would prove troublesome once placed into service. (That was the largest source of warranty issues for my folks.)
The tendancy towards heavy but not especially strong laminates meant that boats were often over their design weights and which were also often under-ballasted. That combo would result in some mix of less stability, less carrying capacity, and a more uncomfortable motion than would be expected if the boats were built as designed for other building venues.
The list could go on and obviously there was some variation between individual yards and individual importers. At some level it is not far to solely blame the yards for the corner''s that were cut. It was often the importers who set or failed to set the standard as to what would be an acceptable quality level.
All of that said, I personally would probably be comfortable buying some of the better built boats from that era. I am a big fan of the (non-Formosa built versions) Kelly-Peterson 44/46''s for example. I would rule out any boat that had teak decks in that the cores are likely to be plywood which is far more rot prone than balsa.
In the end, these boats are also more than 20 years old. A careful set of prior owners will have upgraded and corrected many of the likely building defects. You are only buying one boat so if you are willing to take the time you should be able to find an example that represents a good mix of a reasonable price, a good initial build quality and a regime of proper mainatenance and upgrading of the boat.