SRM is for babies who do not know how to drive a stick.... I am kidding of course!
I have a base model with the aero package. Though no issues spending the extra +10%, I opted to not buy the sports package. I like my cars in the "raw" and enjoy the excitement of the traditional heel-toe.
In my humble opinion, unless you track regularly, the extra $ is not worth it. Much like the Nav, unless you travel a lot, how often will you be utilizing it?
Don't get me wrong, sometimes I wished I bought the sports model. But wishing is normal and we never get satisfied.
If money is no issue, buy the extra options. There is no substitute knowing that your Z is "Fully Loaded.". Plus it would be one less thing for you to say "I wished that....."
good luck.