I'm currently testing the latest stable Opera 10 alpha release (gcc4-qt3-build). Beside being the first able to try out DragonFly, I've ran over the ACID3-test page - and it opened and displayed it if there was no difference to other pages 8-o

Lets have a nice comparison (left side: Firefox 3.0.4 w/ lotsa extensions, right side Opera 10.00, Build 4102, clean install):

BTW: Software plattform in this case is Ubuntu Linux 8.04.1 LTS, kernel 2.6.24, and yes, thats XFCE 4 decorations you can see in the image above