I too am less than excited by nKPs FFB. It has moments of magic, and moments of sleep, mostly the latter.
However, I am willing to write it off as being a bug (highly likely) or a configuation error (what windows settings does nK work best with. LFS ones?. I'm using Linear and 100% FFB on a G25), and will only do a fiar comparison next year or so when the next patch is released.
I am willing to state that is, at the very least, the second best FFB out there (not including RBR - I don't have enough experience on gravel with 4WD to comment, but it feels okay, if a little 'electronic' rather than smooth). In LFS I can feel tyre sidewall flex, in nK I sometimes struggle to feel the whole car move.