On the bringing to a halt, to me one design choice is whether one wants to retain fail without setbacks. A benefit is that a player can attempt things where the cost of failure is simply not achieving the thing, rather than invoking additional badness. (Punished for trying.) On the other hand, fail without setbacks can feel static: it only obliquely drives momentum to fiction. Not necessarily in a bad way - for instance it can put it back on players to switch plans.
Anyway, I wondered what you take is on that?
Well, honestly, for general purpose usage I'm not sold that either fail-with-setbacks or neutral-fail are virtues. To use the Chill example again, a fail will give you motion forward, but minimal; it doesn't set you back but it doesn't advance your progress as much as a success or a critical will. Even a fumble is more of a mixed bag than an unmitigated disaster. For some sort of very simulationist oriented kinds of campaigns this is probably not a good model, and its used where it is simply because Chill is a monster-hunting game and there's always a risk of stalling out otherwise (its a different take on the principals used in Gumshoe in a way), but I came to very much appreciate it in play, and I suspect something like it would be virtuous in most types of campaigns.