PureData has a very outdated looking GUI. Actually, it even looks as if the elements are rendered wrong. This has always driven me away from using it. This new thing has a much more pleasant looking GUI. Promising.
My issue with the PureData UI was that it was a RSI factory. Constantly having to precisely mouse-drag connections between the teeny-tiny ports on the objects:
FWIW, there is a current effort of rewriting the GUI backend to move away from Tcl/Tk and allowing alternative GUI implementations. It will take some time though.
Personally, my main problem with the current Tcl/Tk GUI is that it's also painfully slow...
https://puredata.info/docs/wiki_doc_Images/StartHere/oscMult...