To OP
Honestly you did the right move in getting the SPL.
Im just giving my personal hands on experience with Rear SpC that i have used it for 2 years not have any issues with it.
So other forum members would have the opportunity to know that it would be fine to have SPC for DD. Depending how you want to drive your Z.
Unless the intension is to track the car or constantly drive it like they stole it, then I'll go for SPL anytime of the day.