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Basically all I can say is try it for a while and see if you experience the advantages fanboys such as myself do. Theorizing or explaining only go so far.
Now, I am about to download 8.02 and I hope, but doubt, that they have fixxed some truly idiotic user interface changes they made from 7.xx: 1.) Eliminating the little close-page "x" in the upper RHS, and 2.) Making the security/view images toggle/view style toggle/etc. icon bar - usually to the left of the address bar - disappear while a page is loading. These UI features have actually been standard since I started using Opera in 1997, and there is no discernable advantage to the change. It is little things like that that highlight the virtues of open source. (BTW, if my experience is some artifact of using Win98 SE, someone please tell me.)