So far, this is what I really notice: Opera 9 is very ver fast – both launching and retrieving web pages. And, compared with Firefox, it consumes only half the system resources; with equal numbers of tabs open, Firefox packs a wolloping 100,000KB, whereas Opera makes do with about 50,000KB (according to the Windows Task Manager -> Processes – Mem Usage).
But … on the downside, Opera still has huge display issues. Some web sites are not really usable – Google Mail would be the most glaring example. Boy, do they need to work on that back in Norway.