Fluid doesn't really have anything to do with CSC failure. The internals are plastic - it can't take much abuse. Just have a plan in your back pocket for when it does fail. I recommend the ZSpeed Heavy Duty CSC or Z1 CSC Elimination Kit rather than another OEM one prone to failure.
If your car is new, you really don't have anything to worry about for a while (unless you plan on lots of abuse like Fountain mentions). I have a 2011 Z with 50K miles - I drive it hard but I'm not that abusive. I haven't had any troubles with it, yet, although I'm ready for it to crap out at any time.
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2011 370Z 6MT Sport Gun Metallic | ARC | CJM | Ecutek | FI | Fujimura | R2C | SPL | Stillen | TWM | Z1 | ZSpeed | |