I would be concerned that needle runners on a direct drive would lessen the positive effects...and the reason I use direct drives in the first place.
what I like is the "bite" I get from the needle oscillating in contrast to the "rubbing" effect I get with other rotaries. -granted, I use my swiss knockoff for b/g...but for color or lines, that oscillation really helps.
could the needle be spitting because the needle isn't centered front to back properly?
I really don't remember if I have gotten any spitting on my direct drive rotaries in a while, and I use really light tension on my elastics.