What about the AIDC F-CK-1 Ching-kuo, surely as a twin engine aircraft it would sit within the ‘medium’ category of early 4th generation fighter aircraft? Commercially it was… a disaster, with the initial order being cut down and having no export market, but to be able to produce their own fighter aircraft roughly equivalent to what the US and the Soviet Union was fielding at the time (early block F-16s and MiG-29s) was as big accomplishment.

I like the F-CK-1 (you don’t need to censor the U by the way).
but Arthur said the engine had spooling issues because it is based on civilian airliner engine, not a combat one

secondly, if Taiwan were to export it, how would Mainland China react?

The best? Impossible to say without naming criteria, time frame etc.
Most successful? F-16 without any doubt. Over 4500 produced, proved in every conflict it took part in (and there were many). A very good airframe, with great potential for further development (indicated by the steadily growing empty weight), adaptable to every mission, no glaring weaknesses.
The least successful? Unfortunately the MiG-29, which was never used as intended. The fact that in most conflicts it was used in the least capable variant MiG-29B also greatly hampered its reputation (being outnumbered and without any situational awareness did not help as well). The airframe, while certainly very capable, was crippled by the designers’ decision to go with auxiliary intakes, making it extremely short-legged. The collapse of USSR was a tragedy for this plane, if the MiG-29M ever went into serial production during 90′ we would have a completely different conversation..

ok lets say you were a time traveller who had to advise some one who had to make this decision in the late 80s or early 90s, thus no Gripen to choose from.

http://indianexpress.com/article/india/india-news-india/china-j20-stealth-fighter-rafale-indian-air-force-3737350/

INDIAN AIR MARSHAL says J-20 not so stealthy, Rafale more stealthy!

Actually j-20 is very agile. it has many more lifting and control surfaces than pak-fa
you can see in this picture.

the article assumes they have the same rcs and radar range, thats why it will be a dogfight. pakfa- is just a prototype stage, so we won’t know its radar performance. but we can make strong guesses on its power. look at the radome

now look at J-20

Pak-fa is long but very flat. that mean the radome is smaller
look at the j-20. the Radome is huge.
to put it simply, bigger radome fits bigger aesa radar, better range and detection. pak-fa is limited due to size, just like tejas.
j-20 will find the pak-fa first. pak-fa is more comparable to j-31

the reason why Russian planes are so agile is because of design philosophy. Soviet and Russian planes were always behind US and European ones in radar range, accuracy and reliability. So Russia placed more emphasis on dogfighting, with IRST and helmet mounted sight and other stuff. they plan to win in there.
but most fighting of today and tomorrow will probably be medium and long range. so the tvc of pak-fa is not as special. that is why US and China stopped with tvc and why the US 6th gen fighter are all interceptors.

lol big nose..

wasn’t there some one else in this forum who also always went off about big nose?