Honestly, I'm bored with Opera fanboys who always say that "Opera is the first browser that does xyz feature." If Opera is good as acclaim, the market share will show us the real truth.
As a good geek, I've tried Opera several times since its incarnation. Can't use it longer than few minutes. I think I have no bias. I have no problem for browsing with Safari, Chrome or even IE. But for Opera, it sucks.
(Btw, whoever wants a widget in browser? BitTorrent? email client?)
Straight to the point, it's my job to try Opera 10. If it's good enough, I'll change my mind, review it and advocate it. Anyway, the moment it was starting for the first time, I know that was hell. Opera is written on Qt and running Qt application on GTK+ is sin.
This issue is not Opera's fault anyway. After few googling, I can find the reason behind this. GTK+ style widget is feature of Qt4 and above but the default Opera download package is Qt3. The fix is easy, uninstall the exist Opera and download a new one from Opera FTP. Don't forget to choose "qt4" version.
