Windows version of Firefox in wine vs. Linux version of Firefox

I compared the firefox 3.0.4 windows version (under wine 1.1.4) and the Linux version of firefox 3.0.4. The result is surprising: the windows version runs faster under wine than the native Linux Firefox under Ubuntu.
While the windows version running in wine reacts on window zoom immediately, the Linux version spends 1-2 seconds on this operation ( core 2 duo 2GHz CPU).

Running the online javascript benchmark:

http://celtickane.com/webdesign/jsspeed.php

the windows also outperforms the Linux one.

I m disappointed. I think this can be a deal breaker for the new Linux users.