Having owned 1 C6Z06 (#508) and 2 C5Z06's among a Lotus Esprit V8,
and too many BMW's to count.. including a new E90 M3.
Get the M3.
The problem with the Z06 isn't the car.
I could go on for pages, tens of pages - maybe a hundred even!
The Z06 is a fun car to drive - and most of those who own them are very
much performance oriented drivers - but the quality and backup you get
from GM just isn't there.
(The Z06 has a different owner than the "regular" 'vette for the most part)
Would I own another Z06 - sure as my 5th car.
With my first being my E90 M3, my second being Lisa's future X5 3.0SD, and
our '00 MZ3 as #3, and my trust Jeep as #4.
And I'm sure I'd take even more
heat (and s**t) from BMW owners because
I owned a Z06 (again) and said nice things about it (again).