They are quite different types of lathe……the Schaublin is an instrument lathe and is intended for small precise components that don't need any threading….the Hardinge is a more general piece of equipement that can carry out screwcutting tasks…..
Hardinge are superb and very versatile but Schaublin are more conservative in design and, for me, less interesting if you wish to make complex components. Also, Schaublin does'nt come cheap, or even competitive.