Re: Power consumption - No its not.... i just ran the tests...
i got the latest version of opera and made sure i had the latest chrome and ran all those tests u linked... these are my results.
http://test262.ecmascript.org - Both passed the ch07 tests fully
http://acid3.acidtests.org - Both got 100/100
http://html5test.com/ - Chrome =434 - Opera= 404 (419 when hardware acceleration enabled)
Hardware acceleration is disabled by default as well, which unless you know about it and can be bothered to Google how to turn it on (as it isn't in settings>prefs) makes it a Fail for me...
are you sure you are looking at Opera when you compare the results...?