There's no hardware acceleration yet, but it could be coming in a further dot release and benefit XP users as well as Mac, Linux and Windows 7/Vista users.
Actually, it does have the ability to use hardware acceleration for graphics in both opengl and direct3d, it just has not been implimented in general release versions of opera yet. See this discussion for more details and a post by an Opera developer. Currently, as the links mention, Opera's rendering engine is pure software, but it seems to keep up well enough with the browsers that have opted for hardware acceleration so far. I'm guessing they wont implement it until they can make sure it works on Windows/OSX/Linux/Unix, since they try to keep uniform support most of the time on all major Operating Systems.
I've been a long time Opera user, switching from Mozilla (pre firefox) to Opera when it became free (as in beer). However, I do get irritated by their efforts to keep up with Chrome's speed while screwing over long time users (they cant win that fight in the long run anyways, Google has way too much money). Numerous bug reports on long time stable features and major regressions happen every time they release a major update for Opera and take months or years to fix. From Opera 10.5 to pre 11, tool tips would cover up other applications even if Opera was located in the background. If you happen to have a mouse with arrow buttons for back and forward, the forward arrow button has been broke as far as using the "fast forward" feature since 10.5. At one point, during the version 11 betas, the arrow buttons were broke period (though it was a development release so one cannot really complain about that). With Opera 11, their famous mouse gestures are also partially broken with their implementation of a graphical interface for showing what gestures do what when you hold down the right mouse button. One of the more useful gestures was "right" + "left" + "right" (closes the current window). Now, with the changes they have made, this gesture only works half the time, but they have said they will fix it, but it's tied into the UI they implemented, so it will probably be a while.
They do generally listen to their users. They decided to force chrome like urls on their users during the Opera 11 development (removing "http://" and any of the args after *.com such as ?id=12345) claiming it would make users less likely to click fraudulent links. However, if you're a developer, seeing the arguments is a must and not seeing "http://" or "https://" or "ftp://" is just kind of silly, since sometimes you like to know what protocol you are using instead of guessing through some abstract replacement graphic. Since opera has never been a browser to appeal to novice internet users, dumbing it down seems kind of counter intuitive.
Opera is still my primary browser (except for development--I prefer Firefox/Firebug for that over Opera Dragonfly, but it seems every new version they release, I dread what long time feature they will break next. They haven't frustrated me enough to want to modify the Chromium source code to natively have all the features of Opera, but I wouldn't hold my breath on it for Opera 12.