In reference to Opera being faster etc. have a look at this:
http://www.apple.com/uk/safari/
Although it's presumably biased towards the Safari browser (as it was done on an iMac running Windows XP), it's likely to be unbiased about FF and Opera.
As you can, the only time that Opera is markedly better is with JavaScript Performance, and even then it's less than a second's difference, and on HTML performance, FF is nearly 3 seconds faster (half the time). I'm sorry, but I've tried all 4 of those broswers, and there isn't much difference, but IE 7 is definately slower, and I would say Opera adn FF are about equal on processing power and load times. Also I would say running them on this PC is about equal to the Wii, as the one I use for Internet Browsing has an 800mhz PIII, 256mb of RAM and 32mb nVidia TNT2, which I presume is fairly close to the Wii's specs.
One person's experience or opinion never shows the general consensus
PSN ID: Tispower
MSN: tispower1@hotmail.co.uk
