The vette may be faster, but it's not as refined, or as nice to drive as the M3. It only has 2 seats and it's much less daily-driver friendly. Apart from that, even though I don't find that the car is ugly, it's too much shouty and cheese. (kind of vulgar in this days).
That's why it has lost market Vs the european models, even though it's a bargain (performance Vs speed). I really think it's a great car, specially now that they offer the option for full leather interior, but I wouln't buy a vette over a BMW, Audi, MB or other european cars.