From an audio processing perspective...
My first introduction to a visual programming environment was Reaktor, then Max, then Pd. Only recently did i find out about plogue bidule. As far as interface goes they seem quite similar, and one obviously must consider that the commercial products have customer support rather than the community effort that is PD (which is great, don't get me wrong) and the "user friendliness" approach they must have in order to appeal to users.
As far as i know, reaktor and plogue bidule have VST capabilities, i believe the last i read about the [vst] object in Pd was that is was generally defective (can anyone confirm or correct this?). Max seems to be the largest and most complex of all (The creators of the Monome http://monome.org/ and OHM64 http://www.lividinstruments.com/hardware_ohm64.php both designed their product with max, although i'm sure it could have been with Pd just the same). correct me if i'm wrong, but i understand that pd and max are the most powerful, although i've yet to build anything that sounds as good as what i was able to make in reaktor, and i have no idea about the sound quality that can be achieved with plogue bidule.
your thoughts?
jeff