My arguement is just that Opera has excellent rendering.
It's good, but it is not as close as being CSS2 compliant as Firefox is. Would be my second browser of choice as it is rich in features.
Even FF isn't perfect:
Standards support
Firefox market share
by version[17] Firefox 1.0 0.39 %
Firefox 1.5 0.69 %
Firefox 2 13.75 %
Total 14.83 %
Mozilla Firefox supports many web standards, including HTML, XML, XHTML, SVG 1.1 (partial)[18], CSS, ECMAScript (JavaScript), DOM, MathML, DTD, XSLT, XPath, and PNG images with alpha transparency.[19] Firefox also supports standards proposals created by the WHATWG such as client-side storage,[20][21] and canvas element.[22]
Although Firefox 2 does not pass the Acid2 standards-compliance test, development builds of Firefox 3 do.
SourceRon
Edited by Major Payne, 23 November 2007 - 11:44 PM.