What I don't understand...There were some issues about the GUI from Phosycon thats clear for me.
But Nepheton & Drumazon still use a GUI that looks like a 909,808 and Drumazon also uses some 909 sounds (like clap,ride,hats and cymbal) isn't this a problem (I don't care but im just curious

When i'm listening to your VST's (I own all of them) they come really close to the original but still i'm missing some small things which I will describe here:
Nepheton: The bassdrum is too ''clicky'' I would like to have some more boom and less attack.
Drumazon: The original is not so clean, I'm missing some kind of noise in the kick
Phosycon: The original 303 has some kind of saturation/bite in the higher frequencies and sounds more ''clicky'' (maybe from a VCA which is triggered by the sequencer) and also more noisy
I don't know if you're planning to optimize this plugins (they already sound good IMO) but when it's possible it would be nice to have an ''vintage'' option with all the imperfections and noisyness.
In another thread i suggested to create a plug in wich emulates tape (compression),non static vinyl emulation and AD noise or something like that. Don't know if its possible but it would be nice and unique.