I use Opera every day. Correction, I used to use Opera every day when I
was on my--now history--Win2Kpro platform. I'm at about day 3 of my
"convert to Kubuntu 7.10" project and have yet to install it on my new
desktop.
I bought 4 licenses to Opera probably 5 or more years ago now, 2 for
OS/2, one for WinDoze and one for Linux and have been using it since
v5.1 or so. Once you ascend the learning curve to use all of its
features, it is very difficult to go back to Netscape, Mozilla, or
FireFox. It is lightning fast, mouse gestures make navigating websites
extremely intuitive. Run it up to 30 tabs and the mouse-over preview of
the page under the tab becomes invaluable, tabbed windows are resizable
so you can drag links from the eBay listing and drop them into another
window. It just empowers you on the web.
I can easily understand why your client is addicted and I think I'll see
about getting it installed on my new system now.