I'd rather be able to use the wheel to zoom the window as I feel like it. Sometimes I want to sit back and relax and read something; other times I'm in normal work position closer to the screen. So, I want to just disable the font size pegging. Use their size as a starting value, sure. I think Opera zooms by changing the window world coordinate system mapping, so a "8 point font" can be an inch tall, without the layout engine caring or being any the wiser. And that scales the images, too!
No, I've not tried Mozilla except once in the very early days. Maybe I'll give it a shot. I'm hooked on the Google toolbar, though... and things like MSDN and CHM files insist on using IE, so I'll have to know two systems.