The shaft one-way will give you a tiny bit more steering and no brakes.
I never really thought it was worth losing the brakes for so little extra steering.
The front oneway is a different animal entirely. The car feels on edge most of the time and doesn't have any differential action whatsoever when you are accelerating. This can be great on smooth, low-grip tracks but on bumpy high-grip stuff it can veer off suddenly. It becomes more of a point and shoot affair with the oneway diff.
If you are running tight and twisty stuff on high grip I'd go with a diff. If it's long, smooth and open the oneway can be better.
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