In my definition, 'radical' would be a formation demanding the immediate nationalisation of most of the economy, or a party associated with groups beating up factory owners on the streets and shouting "death to capitalists!" on football matches, or the re-naming of BDR into DDR with the re-adoption of the old flag and coat of arms. Just to keep up the symmetry with what counts as 'radical' on the rightward direction.

I note that permanent observation of the PDS by the Verfassungsschutz failed to find it problematic.

Without agreeing with the DDR-apologists among the Linke, I will note that there is a wide range of historical interpretations among former inhabitants of the Eastern Bloc, and judgements of developments don't rely on per capita GDP only. This is as true for the ex DDR as Hungary. You may be surprised to learn that a not insignificant part of the Right here thinks that it was better under Kádár (the post-1956 communist dictator) than today.

Good points in your last paragraph.

_{*Lunatic*, n.
One whose delusions are out of fashion.}