the difference between the autostick and the manual was night and day for me. I did not want the car after driving the autostick. It is not a triptronic and manual mode is unusable. In manual mode you tell it to shift, then wait for it to think then it finally shifts.. it still shift on you even in manual mode so I don't see the point. Plus it did not feel very fast.
I went back and tried the manual and really liked it. It had more push to it and I was in control. considering that most of the power kicks on at 3000 rpm I am able to stay above their when driving to stay in my power band (yeah I have a bigger gas bil lthen the norm). You should diffently try the Manual.
As far as the 350z yeah it has more power but weighs a ton too. We even have wider tires than the 350z. I looked at the RX-8 and the 350z when deciding to buy mine.
Personally I did not like the 350z at all. I never even took the test drive but got in and out of a few models. When you see it up close you will notice how unporpotional the car really is. The body is too wide at some points (espically the rear with those little tires). The worst part was the interior. The carpet looked like they got a really good deal on the cheapest carpet ever made. The interior overall looks cheap and unfinished. Even the leather package was not nice.
Either you will love or hate the 350z, there is no inbetween. If you decide that you do love it then you may want to look into a aftermarket leather interior. Looking at all the options your best bet is to buy the cheapest one and just add aftermarket leather inside. They are charging to much for what little they add to the price of the grand trouring model. You don't really need xenon lights 1" bigger rims and all the ESP stuff.
As for the Crossfire the base model has no accent colors. This allows it to be disguinished from the limited model. If you ask me it is a shame they even offered this model. It brings resale down. For a "flagship" car they should have never stripped it. Have you ever seen a new Corvette without leather interior? DC just downgraded the class of the car.
-marc