Thanks everyone, you all make very good points!
I did 2 solid months of research on the Z and was 98.5% positive a new one was the car for me (LED fanboi lol) and just recently started entertaining the possibility of a Porsche. Maybe it's bc all three cars I've bought were new, but I definitely put weight on knowing every mile that is put on a car.
I was looking into a 6mo old Audi before I bought my Golf R, but couldn't come to terms with paying $40k for a car with a one inch scuff down the center console, just didn't feel right to me.
While I'm sure the Porsche would offer much better quality and equal if not slightly better performance (If I went with an S), I think my perfectionist side wouldn't let me look past the usual bumps and bruises that come with buying a car someone else has gotten in and out of a thousand times.
I keep trying to second guess the Z, but no matter what I explore I just realize I'm even more impatient for her to arrive!