I find FAXXO harder then FELMO's chart harder to read (on the screen anyway). FELMO has more stupid jump patterns while FAXXO has longer 400bpm 8th streams.
HDVO (not sure why its not mentioned yet) has 8th streams at 'only' 360bpm but it involves crossovering, so its just a more hax version of PSMO.
Still, Vertex^2 expert > all.
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