by DarkStar » Tue Jan 14, 2020 11:41 pm
Correct.
ST3 is able to Import "Legacy" libraries such as MP1, Sonik Synth 2, SampleMoog, SampleTank Xpansions etc. ST3 will create new copies of those libraries in ST3 format. It will not overwrite the legacy libraries themselves.
ST4 cannot Import older libraries. But it can load ST3 instruments. So the approach is to Import the old libraries using ST3, then set ST4 to access its own library and the ST3 library (which will then include the Imported legacy libraries).
Syntronik is similar to ST3, with some extra features. But it can only load its own instruments (which are in ST3 format). And, on installation the library should be installed into the ST3 library, by using the SAME disk path as used for ST3. That way, ST3 can load the Syntronik instruments too.
As for which one to choose, it all depends on what sounds you want. ALso, the Syntronik v1.2.0b installer IS compatible with Catalina.