i had this clutch on the S15 and i loved it.
i didnt get the chatter because being a 2ltr 4cyl, you needed to keep the revs up around 3000rpm for just normal crusing [well thats how i drive it anyway, with the vq its different i cruise around 1800rpm]
it was so grabby, i remeber clutch kicking and putting 20psi and 250kw through the rear wheels and it was ALL going to the rear wheels... no clutch slipping awesome power delivery it was a great piece of kit.
when i first tried to drive it, it felt so weird, and yes i too stalled it once or twice on the way home. i got used to it very quickly and then it felt great and 2nd nature.
the clutch pedal yes is super soft, almost unbelievable that it is a twin plate clutch.
-mark