For what it's worth I love my Z for exactly what it is, RTB summed it up perfectly. I also love my bike, Honda SP2, not the lightest, fastest, most powerful or newest but it exudes character, just like my Z. Just like my bike if you want to modyfy it then the sky (wallet) is the limit, it's very easy to personalise and create something that suits you.
For me, cleaning the Z and keeping on top of the finish is enjoyable and satisfying...driving the beast is even more so!
If you can find so much wrong with the Z then ownership of this car is not for you, I for one think I spent my hard earned money wisely.