The OS Giken is more race oriented as it is a full-locking clutch-type diff. I think it all depends what you use it for. The Quaife is going to be (much) lower maintenance, but technically a step down in terms or pure performance. Candidly, I think the OS may be overkill in our rides, but it is all about where you choose to make compromises.
The non-TCD version will also be more noticeable audible when compared to the Quaife.
Btw, the OSs are OEM in many high end performancvehicles (think m and AMG), thus it is not too much of a stretch to put it in our rides. I just have trouble justifying the price point differential for additional maintenance and little added capability in most daily circumstances.
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