This was my though after I installed the Opera 11 beta (11.00b1). I installed it first on my Windows 7 virtual machine and the speed of the installer was impressive. It took about half a second and Opera was installed. I was actually worried if something was wrong but after another second Opera was up and running. Not what you expect if you're used to the good old MSI based installers.
My CPU is a relatively old Core 2 Duo E6300 (the slowest of the early Core 2 Duos) and within the VM video-playback with Firefox or Opera usually is a joke. More out of fun I opened a video of the events.mi archive… and was impressed. You could actually watch the video fluently and the sound was in sync, too. To be honest I haven't tested the Firefox 4 beta so I have no idea if they are as fast as Opera but still, it's impressive.
Another nice test is my own website. Opera 10 had a somewhat annoying bug with box
shadows: with smooth scrolling drop shadows outside of their box were not always draw,
giving some strange artifacts sometimes. This is fixed with Opera 11 and it looks like the
performance of these effects improved as well. Since my website makes heavy use of drop
shadows I'm very happy about this. In some highly subjective and totally unreliable testing
done on an old Pentium M 1.5 GHz notebook it was even faster than Chrome (quickly
scrolling up and down my website). This places Opera again on the top of my favorite
browser list because Chrome has an annoying bug with inset dropshadows and rounded
corners (the corners are not rounded and drawn in a strange light color). Thanks to the
-webkit- prefix I just disabled them for Chrome (I'm sorry if I accidentally screwed some
Safari or Konqueror).
There is much other stuff like tab grouping and the visual mouse gestures. Nothing of it is actually new but it's very well integrated into the rest of the browser. Exploring the mouse gestures is quite funny (at least for me). Anyway, I have a new toy to play with. :)