i tripped over opera sometime ago, and uses Opera 90% of the time, but IE is still my default browser because it works with almost all sites (esp international sites) whereas opera is little buggy w/ certain ones.
things that really shines in opera over IE
1. when you want to go back to a form where u just filled pages of texts, if you press back in opera, everything that you did (checkmark, etc) is still there, w/ IE (and most of times, not all times) the checkmark and the text is gone, and if you haven't copied it, you have to type the damm lines again!! .
2. the tabs at the top rather thatn IE's taskbar-space-easter is much better when doing alot of things,
bad,
1. certain web-site having problme w/ O7. but i'm sure it'll be fixed
2. eats more memory than IE (i blieve),
final.
i'd love to pay for the Opera, it's certainly Excellent program; fast, convinient, and better looking! no complaints from regular user like me