Biggest issue for '09 Z is that
Shunya doesn't have it yet. There must be some sort of TSB out.
Kidding aside, I honestly don't have any deal breaking issues with my car. The road noise is probably the most annoying, but it only occurs on certain road surfaces. IIRC, some different tires can alleviate this issue. The transmission will be notchy for the first few thousand miles, but it is much better than my 350Z (with transmission replaced in '06). The clunkiness and rattling noise is apparent in the Z/G, so nothing new there.